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Full text of "NB NBIC 2 (2007): 2008 Addendum to Part 2"

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NOTICE OF INCORPORATION 

United States Legal Document 

J^" All citizens and residents are hereby advised that 
this is a legally binding document duly incorporated by 
reference and that failure to comply with such 
requirements as hereby detailed within may subject you 
to criminal or civil penalties under the law. Ignorance of 
the law shall not excuse noncompliance and it is the 
responsibility of the citizens to inform themselves as to 
the laws that are enacted in the United States of America 
and in the states and cities contained therein. "^& 

* * 

NBIC 2007, National Board Inspection Code, 

Part 2, Inspection, 2008 Addenda Release, 

as mandated by the requirements of the States 

of Alabama, Alaska, Arizona, Colorado, Iowa, 

Kansas, Michigan, Missouri, Nebraska, New Jersey, 

North Dakota, Ohio, Oregon, and Utah. 





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g^EEj|2E 




Th e 

ATIDNAL 



Board 

of Boiler and 
Pressure Vessel 
Inspectors 




Nsitionsil 
Board 

Code 



Part 2 - Inspection 



NATIONAL BOARD INSPECTION CODE 



NOTE: Pages ii through xvi are not part of this 
American National Standard 



Library of Congress Catalog Card No. 52-44738 

Printed in the United States of America 

All Rights Reserved 

© 2008 
The National Board of Boiler and Pressure Vessel Inspectors 

Headquarters 

1055 Crupper Avenue 

Columbus, Ohio 43229-1183 

614.888.8320 

614.847.1828 Fax 

Testing Laboratory 

7437 Pingue Drive 

Worth ington, Ohio 43085-1 71 5 

614.888.8320 

614.848.3474 Fax 

Training & Conference Center 

1 065 Crupper Avenue 

Columbus, Ohio 43229-1 1 83 

614.888.8320 

614.847.5542 Fax 

inspection Training Center 

1075 Crupper Avenue 

Columbus, Ohio 43229-1 1 83 

614.888.8320 

614.847.5542 Fax 



NATIONAL BOARD INSPECTION CODE 



The National Board of Boiler and Pressure Vessel Inspectors 
Board of Trustees 

R.J. Aben Jr. 
Chairman 

M. Mooncy 
First Vice Chairman 

J.T. Amato 
Second Vice Chairman 

D.A. Douin 
Secretary /Treasurer 

J.M. Given Jr. 
Member at Large 

D.J. Jenkins 
Member at Large 

D.C. Price 
Member at Large 

B. Krasiun 
Member at Large 



Advisory Committee 

G. W. Gaianes 
representing welding industries 

E.J. Hoveke 
representing National Board certificate holders 

L.J. McManamon Jr. 
representing organized labor 

G. McRae 
representing pressure vessel manufacturers 

B.R. Morel ock 
representing boiler and pressure vessel users 

C.E. Perry 
representing boiler manufacturers 

C.G. Schaber 
representing authorized inspection agencies (insurance companies) 



NATIONAL BOARD INSPECTION CODE 



National Board Members 

Alabama Ralph P. Pate 

Alaska Chris Fulton 

Arizona Randall D.Austin 

Arkansas Gary R. Myrick 

California Donald C. Cook 

Colorado Steve Nelson 

Connecticut Allan E. Piatt 

Delaware James B. Harlan 

Florida Michael A. Bums 

Georgia Carl Everett 

Hawaii Keith A. Rudolph 

Idaho Michael Poulin 

Illinois 

Indiana Daniel Willis 

Iowa Michael Klosterman 

Kansas Donald ). Jenkins 

Kentucky Rodney I landy 

Louisiana William Owens 

Maine John H. Burpee 

Maryland Karl J. Kraft 

Massachusetts Mark Mooney 

Michigan Robert |. Aben Jr. 

Minnesota Joc;l T. Amalo 

Mississippi Kenneth L. Watson 

Missouri Gary Scribner 

Montana Timothy Stewart 

Nebraska Christopher B.Cantrell 

Nevada Roy Perry 

New Hampshire Wayne Brigham 

New Jersey Milton Washington 

New York Peter L. Vescio 

North Carolina Jack M. Given Jr. 

North Dakota Robert Reetz 

Ohio Dean! Jagger 

Oklahoma Tom Monroe 

Oregon Michael D. Graham 

Pennsylvania Jack A. Davenport 

Rhode Island Benjamin Anthony- 
South Dakota Howard D. Pfaff 

Tennessee Audrey E. Rogers 

Texas Anthony P. Jones 

Utah Rick Sturm 

Vermont Wesley E. Criderjr. 

Virginia Edward G. Hilton 

Washington Linda Williamson 

West Virginia 

Wisconsin Michael J. Verhagen 

Chicago, IL Michael J. Ryan 

Detroit, Ml John E. Bell 

Los Angeles, CA Jovie Aclaro 

Milwaukee, Wl Randal S. Pucek 

New York, NY William McGivney 

Alberta Ken K.T. Lau 

British Columbia John G. Siggers 

Manitoba Terry VV. Rieger 

New Brunswick Dale F. Ross 

Newfoundland & Labrador E. Dennis Eastman 

Northwest lerritories Steve Donovan 

Nova Scotia Peter Dodge 

Nunavut Territory 

Ontario Trantisek Musuta 

Prince Edward Island Kenneth Hynes 

Quebec Madiha M. Kotb 

Saskatchewan Brian Krasiun 

Yukon Territory Daniel C. Price 



NATIONAL BOARD INSPECTION CODE 



National Board Inspection Code Committees 



Main Committee 



T. Parks, Chair 

The National Board of Boiler and 

Pressure Vessel Inspector'. 

R. YVielgoszinski, Vice Chair 
Hartford Steam Boiler Inspection and 
Insurance Company of Connecticut 

R. I lough, Secretary 

The National Board of Boiler and 

Pressure Vessel Inspectors 

R. Aben 

State of Michigan 

S. Bacon 
Conoco Phillips 

P. Bourgeois 
Travelers 

D. Canonico 
Canonico & Associates 

D. Cook 

State of California 

P. Edwards 

Stone & Webster, Inc. 

G. Calanes 

Midwest Generation EME, LLC 

J. Given 

State of North Carolina 

F. Hart 

Furmanile Corporation 

C. Hopkins 
Seattle Boiler Works 

D. Parrish 
FM Global 



J. Pillow 

Common Arc Corporation 

A. Piatt 

State of Connecticut 



R. Reetz 

State of North Dakota 



H. Richards 
Southern Company 

J. Richardson 
Consultant- Dresser Inc. 

C. Scribner 
State of Missouri 

). Sekely 

Wayne Crouse Inc. 

R. Snyder 
ARISE, Inc. 

S. Staniszewski 

(,'5 Department of Transportation 

R. Sulzer 

The Babcock & Wilcox Company 

1 1. Titer 

MIRANT Mid Atlantic 



J. Yagen 
Dynegy, Inc. 



NATIONAL BOARD INSPECTION CODE 



Subcommittee for installation (Part 1) 



H. Richards, Chair 
Southern Company 

C. Hopkins 
Seattle Boiler Works 

I'. Bourgeois 
Si. Paul Travelers 

G. Hallev 
ABMA 

S. Konopacki 
Midwest Generation 

B. Moore 

Hartford Steam Boiler Inspection 



A. Piatt 

State of Connecticut 

C. Scribner 
State of Missouri 

R. Snyder 
ARISF, Inc. 

R. Sulzer 

The Babcock and Wilcox Company 

H. Tiler 

MIRANT Mid-Atlantic 

|. Yagen 
Dynegy, Inc. 



Subgroup for Installation (Part 1) 



Boilers 

C. Hopkins, Chair 
Seattle Boiler Works 

P. Bourgeois 
.St. Paul Travelers 

C. Halley 
ABMA 

S. Konopacki 
Midwest Generation 

B. Moore 

Hartford Steam Boiler Inspection 

A. Piatt 

State of Connecticut 

C. Scribner 
State of Missouri 

R. Sulzer 

The Babcock & Wilcox Company 



Pressu re Vessels and Piping 

J. Yagen, Chair 
Dynegy, Inc. 

H. Richards 
Southern Company 

G. Scribner 
5(ate of Missouri 

R. Snyder 
ARISE, Inc. 

H. Titer 

MIRANT Mid Atlantic 



VI 



NATIONAL BOARD INSPECTION CODE 



Subcommittee for Inspection (Part 2) 






D. Cook, Chair 
Slate of California 


D. Rarrish 
FM Global 




S. Bacon 

Conoco Phillips-Ferndale Refinery 


R. Rcetz 

Stale of North Dakota 




B. Barbato 

St. Paul Travelers 


J. Richardson 
Consultant-Dresser. Inc. 




D. Canonico 
Canonico & Associates 


|. Riley 

Chevron Energy and Technology 




J. Colter 
Worthington Cylinders 


M. Schwartzwalder 
AEP 




P. Martin 

The United Association of journeymen and Apprentices 

or the Plumbing and Pipe Pitt'ng Industry of the United Sts.tcs and Canada 


R. Shapiro 
PacifiCorp 




G. McRae 

Trinity Industries, Inc. 


S. Staniszewski 

US Department of Transportation 




V. Newton 
Chubb & Son 


R. Wacker 
Dupont 





Subgroup for inspection (Part 2) 




General Requirements 


Specific Requirements 


). Getter, Chair 
Worthington Cylinders 


S. Staniszewski 

US Department of Transportation 


U. Canonico 
Canonico & Associates 


S. Bacon 

Conoco Phillips-Ferndale Refinery 


R. Dobbins 
Zurich N.A. 


B. Barbato 

St, Paul Travelers 


M. Horbaczewski 
Midwest Generation 


D. Cook 

State of California 


P. Martin 

The United Association of journeymen and Apprentices 

oi the Plumbing and Pipe Fnting Industry of the { 'n'ted St.ites jntl Cj/uo'j 


R. Dobbins 
7urich N.A. 


D. Parrish 
FM Global 


J. Getter 
Worthington Cylinders 


J. Richardson 
Consultant-Dresser, Inc. 


G. McRae 

Trinity Industries, Inc. 


R. Shapiro 
PacifiCorp 


|. Riley 

Chevron Energy and Technology 




M. Schwartzwalder 
AEP 




R. Wacker 
Dupont 



VII 



NATIONAL BOARD INSPECTION CODE 



Subcommittee for Repairs and Alterations (Part 3) 



C. Galanes, Chair 

Midwest Generation EME, I.I C 

R. A ben 

State of Michigan 

P. Edwards 

Stone S, Webster, Inc. 

) Given 

State of North Carolina 

J. Larson 

OneBeacon America Insurance Company 



F. Ravlovi.cz 

The Bahcoc.k and Wilcox Company 

J. Pillow -Vice Chair 
Common Arc Corporation 

B. Schulte 
NRC lexas, LP 

J. Sekely 

Wayne ('.muse Inc. 

M. Webb 
Xc.cl Energy 



Subgroup for Re pairs and Alterations (Part 3) 

General Requirements 

P. Edwards, Chair 
Stone A Webster, Inc. 

R. Aben 

State of Michigan 

I. Larson 

OneBeacon America Insurance Company 

R. Pulliam 

Ihc Bahcoc.k A Wilcox Company 

B. Schulte 
NRC Texas, LP 

M. Webb 
Xcel Energy 



Specific Require ments 

J. Sekely, Chair 
Wayne C rouse Inc. 

G. Galanes 

Midwest Generation EME, II C 

J. Given 

Stale of North Carolina 

W. Jones 
ARISE, Inc. 

F. Pavlovicz 

The Babcock & Wilcox Company 

J. Pillow 

Common Arc Corporation 



VIII 



NATIONAL BOARD INSPECTION CODE 



Subcommittee for Pressure Relief Devices (Parts 1, 2, and 3) 


T. Marl, Chair 
Turnmnite America Inc. 


R. Donalson 

Tyco Valve and Controls 


A. Cox 
Industrial Value 


K. Fitzimmons 
Carter Chambers, LLC 


J. Bdll 

The National Board of Boiler and 

Pressure Vessel Inspectors 


C. Humphries 
Oxy Vinyls, LP 


M. Brodeur 

International Valve & Instr. Corp. 


R. McCaffrey 
Quality Valve 


S. Cammeresi 
CCR 


1. Pafel 

I arris Engineering 


D. DeMichael 
Oul'ont 





Special Subgroups for Installation, Inspection, and Repairs and Alterations (Parts 1, 2, and 3) 



Locomotive Boilers 




B. Withuhn, Chair 


S. Lee 


Smithsonian Institution 


( Inion Pacific Railroad 


S. Butler 


D. McCormack 


Midwest Locomotive & Machine 
Works 


Consultant t 


D. Conrad 


L. Moedinger 


Valley Railroad Co. 


Strasburg Railroad 


R. Franzcn 

Steam Services of America 


R. Reetz 

State of North Dakota 


D. Criner 


C. Scerbo 


Wasatch Railroad Contractors 


Federal Railroad Administration 


S. Jackson 


R. Schueler 


D & SNC 


The National Board of Boiler andPres- 




sure Vessel Inspectors 


M. lansscn 


R. Stone 


Vapor locomotive Company 


ABB/Combustion Engineering 




R.Yuill 




Consultant 



NATIONAL BOARD INSPECTION CODE 



Special Subgroups for Installation, inspection, and Repairs and Alterations (Parts 1, 2, and 3) 



Graphite 


Fiber-Reinforced Pressure Vessels 


E. Saltow, Chair 

SCL Carbon Croup/SCL Technic 


B. Shelley, Chair 
DuPont 


W. Banker 
Graphite Repairs, Inc 


F. Brown 

The National Board of Boiler and 

Pressure Vessel Inspectors 


F. Brown 

the National Board of Boiler and 

Pressure Vessel Inspectors 


J. Buslillos 

Bustillos and Consultants 


K. Cummins 
Louisville Graphite 


D. Eisberg 

tnergy Recovery Inc. 


S. Ma lone 

Car bone of America 


T. Fowler 
Retired/Spicewood, TX 


M. Minick 
FM Global 


D. Keeler 

The Dow Chemical Company 


A. Stupica 

SCL Carbon Group/SGI. Technic 


R. Lewandowski 

Corrosion Resistant Composites 




1 1. Marsh 
Consultant 




D. Pinell 
ABSIS 




J. Richter 

FEMech Fngineering 



NATIONAL BOARD INSPECTION CODE 



National Board Inspection Code 
2007 Edition including 2008 Addendum 

Date of Issue — December 31, 2008 

This code was developed under procedures accredited as meeting the criteria for American 
National Standards. The Consensus Committee that approved the code was balanced to ensure 
that individuals from competent and concerned interests had an opportunity to participate. The 
proposed code was made available for public review and comment, which provided an 
opportunity for additional public input from industry, acadcmia, regulatory and jurisdictional 
agencies, and the public-at-large. 

The National Board does not "approve," "rate," or "endorse" any item, construction, 
proprietary device, or activity. 

The National Board does not take any position with respect to the validity of any patent rights 
asserted in connection with any items mentioned in this document, and does not undertake 
to insure anyone utilizing a standard against liability for infringement of any applicable Letters 
Patent, nor assume any such liability. Users of a code are expressly advised that determination 
of the validity of any such patent rights, and the risk of infringement of such rights, is entirely 
their own responsibility. 

Participation by federal agency representative(s) or person(s) affiliated with industry is not to be 
interpreted as government or industry endorsement of this code. 

The National Board accepts responsibility for only those interpretations issued in accordance 
with governing National Board procedures and policies which preclude the issuance of 
interpretations by individual committee members. 

The footnotes in this document are pari of this American National Standard. 



n 







w 



The above National Board symbols are registered with the US Patent Office. 

"National Board" is the abbreviation for The National Board of Boiler and Pressure Vessel 
Inspectors. 

No part of this document may be reproduced in any form, in an electronic retrieval system or 
otherwise, without the prior written permission of the publisher. 



NATIONAL BDARD INSPECTION CODE 



XII 



NATIONAL BOARD INSPECTION CODE 



Foreword 

The National Board of Boiler and Pressure Vessel Inspectors is an organization comprised of 
Chief Inspectors for the states, cities, and territories of the United States and provinces and 
territories of Canada. It is organized for the purpose of promoting greater safety to life and 
property by securing concerted action and maintaining uniformity in post-construction 
activities of pressure-retaining items, thereby ensuring acceptance and interchangeability 
among jurisdictional authorities responsible for the administration and enforcement of various 
codes and standards. 

In keeping with the principles of promoting safety and maintaining uniformity, the National 
Board originally published The NBIC in 1 946, establishing rules for inspection and repairs to 
boilers and pressure vessels. The National Board Inspection Code (NBIC) Committee is charged 
with the responsibility for maintaining and revising the NBIC. In the interest of public safety, 
the NBIC Committee decided, in 1 995, to revise the scope of the NBIC to include rules for 
installation, inspection, and repair or alteration to boilers, pressure vessels, piping, and 
nonmetallic materials. 

In 2007, the NBIC was restructured into three Parts specifically identifying important post- 
construction activities involving safety of pressure-retaining items. This restructuring provides for 
future expansion, transparency, and uniformity, ultimately improving public safety. 

The NBIC Committee's function is to establish rules of safety governing post-construction activities 
for the installation, inspection and repair and alteration of pressure-retaining items, and to interpret 
these rules when questions arise regarding their intent. In formulating the rules, the NBIC 
Committee considers the needs and concerns of individuals and organizations involved in the 
safety of pressure-retaining items. The objective of the rules is to afford reasonably certain 
protection of life and property, so as to give a reasonably long, safe period of usefulness. 
Advancements in design and material and the evidence of experience are recognized. 

The rules established by the NBIC Committee are not to be interpreted as approving, 
recommending, or endorsing any proprietary or specific design, or as limiting in any way an 
organization's freedom to choose any method that conforms to the NBIC rules. 

The NBIC Committee meets regularly to consider revisions of existing rules, formulation of new 
rules, and respond to requests for interpretations. Requests for interpretation must be addressed 
to the NBIC Secretary in writing and must give full particulars in order to receive Committee 
consideration and a written reply. Proposed revisions to the Code resulting from inquiries will 
be presented to the NBIC Committee for appropriate action. 

Proposed revisions to the Code approved by the NBIC Committee are submitted to the 
American National Standards Institute and published on the National Board Web site to 
invite comments from all interested persons. After the allotted time for public review and final 
approval, revisions are published annually in Addenda to the NBIC. 

Organizations or users of pressure-retaining items are cautioned against making use of 
revisions that are less restrictive than former requirements without having assurance that they 
have been accepted by the Jurisdiction where the pressure-retaining item is installed. 



NATIONAL BOARD INSPECTION CODE 



The general philosophy underlying the NBIC is to parallel those provisions of the original code 
of construction, as they can be applied to post-construction activities. 

The NBIC does not contain rules to cover all details of post-construction activities. Where 
complete details are not given, it is intended that individuals or organizations, subject to the 
acceptance of the Inspector and Jurisdiction when applicable, provide details for post- 
construction activities that will be as safe as otherwise provided by the rules in the original 
Code of Construction. 

Activities not conforming to the rules of the original code of construction or the NBIC must 
receive specific approval of the Jurisdiction, who may establish requirements for design, 
construction, inspection, testing, and documentation. 

There are instances where the NBIC serves to warn against pitfalls; but the Code is not a hand- 
book, and cannot substitute for education, experience, and sound engineering judgment. 

It is intended that this Edition of the NBIC and any subsequent Addenda not be retroactive. 
Unless the Jurisdiction imposes the use of an earlier edition, the latest effective edition and 
addenda is the governing document. 



XIV 



NATIONAL BOARD INSPECTION CODE 



introduction 



It is the purpose of the National Board Inspection Code (NIBIG) to maintain the integrity of 
pressure-retaining items by providing rules for installation, and after the items have been 
placed into service, by providing rules for inspection and repair and alteration, thereby 
ensuring that these items may continue to be safely used. 

The NBIC is intended to provide rules, information and guidance to manufacturers, 
Jurisdictions, inspectors, owner-users, installers, contractors, and other individuals and 
organizations performing or involved in post-construction activities, thereby encouraging the 
uniform administration of rules pertaining to pressure-retaining items. 

Scope 

The NBIC recognizes three important areas of post-construction activities where information, 
understanding, and following specific requirements will promote public and personal safety. 
These areas include: 

• Installation 

• Inspection 

• Repairs and Alterations 

The NBIC provides rules, information, and guidance for post-construction activities, but does 
not provide details for all conditions involving pressure-retaining items. Where complete de- 
tails are not provided in this Code, the Code user is advised to seek guidance from the Jurisdic- 
tion and from other technical sources. 

The words shall, should, and may are used throughout the NBIC and have the following intent: 

• Shall - action that is mandatory and required. 

• Should - indicates a preferred but not mandatory means to accomplish the requirement 
unless specified by others such as the Jurisdiction. 

• May - permissive, not required or a means to accomplish the specified task. 

Organization 

The NBIC is organized into three Parts to coincide with specific post-construction activities 
involving pressure-retaining items. Each Part provides general and specific rules, information, 
and guidance within each applicable post-construction activity. Other NBIC Parts or other 
published standards may contain additional information or requirements needed to meet the 
rules of the NBIC. Specific references are provided in each Part to direct the user where to find 
this additional information. NBIC Parts are identified as: 

• Part 1 , Installation This Part provides requirements and guidance to ensure all types of 
pressure-retaining items are installed and function properly. Installation includes 
meeting specific safety criteria for construction, materials, design, supports, safety 
devices, operation, testing, and maintenance. 

• Part 2, Inspection - This Part provides information and guidance needed to perform and 
document inspections for all types of pressure-retaining items. This Part includes 
information on personnel safety, non-destructive examination, tests, failure 
mechanisms, types of pressure equipment, fitness for service, risk-based assessments, 
and performance based standards. 



xv 



NATIONAL BOARD INSPECTION CODE 



• Part 3, Repairs and Alterations -This Part provides information and guidance to 
perform, verify, and document acceptable repairs or alterations to pressure-retaining 
items regardless of code of construction. Alternative methods for examination, testing, 
heat treatment, etc., are provided when the original code of construction requirements 
cannot be met. Specific acceptable and proven repair methods are also provided. 

Each NBIC Part is divided into major Sections as outlined in the Table of Contents. 

Tables, charts, and figures provide relevant illustrations or supporting information for text 
passages, and are designated with numbers corresponding to the paragraph they illustrate or 
support within each Section. Multiple tables, charts, or figures referenced by the same 
paragraph will have additional letters reflecting the order of reference. Tables, charts, and 
figures are located in or after each major Section within each NBIC Part. 

Text Identification and Numbering 

Each page in the text will be designated in the top header with the publication's name, part 
number, and part title. The numbering sequence for each section begins with the section 
number followed by a dot to further designate major sections (e.g., 1 .1 , 1 .2, 1 .3). Major 
sections are further subdivided using dots to designate subsections within that major section 
(e.g., 1.1.1, 1.2.1, 1.3.1). Subsections can further be divided as necessary. 

Paragraphs under sections or subsections shall be designated with small letters in parenthesis 
(e.g., a), b), c)) and further subdivided using numbers in parenthesis (e.g., 1), 2), 3)). 
Subdivisions of paragraphs beyond this point will be designated using a hierarchical sequence 
of letters and numbers followed by a dot. 

Example: 2.1 



Major Section 






2.1.1 Section 






2.1.2 Section 






2.1.2. Su 


bsecti 


on 


a) 


paragraph 


b) 


paragraph 




D 


subparagraph 




2) 


subparagraph 

a. subdivisions 

1. subdivisions 

2. subdivisions 

b. subdivisions 

1 . subdivisions 

2. subdivisions 



Tables and figures will be designated with the referencing section or subsection identification. 
When more than one table or figure is referenced in the same section or subsection, letters or 
numbers in sequential order will be used following each section or subsection identification. 



XVI 



NATIONAL BOARD INSPECTION CODE 



Supplements 

Supplements are contained in each Part of the NBIC to designate information only pertaining to 
a specific type of pressure-retaining item (e.g., Locomotive Boilers, Historical Boilers, Graphite 
Pressure Vessels.) Supplements follow the same numbering system used lor (he main text only 
preceded by the Letter "S." Each page of the supplement will identify the supplement number 
and name in the top heading. 



Addenda 

Addenda, which include revisions and additions to this Code, are published annually. Addenda 
are permissive on the date issued and become mandatory six months after the date of issue. 
The addenda will be sent automatically to purchasers of the Code up to the publication of the 
next edition. Every three years the NBIC is published as a new edition that includes that year's 
addenda. 



Interpretations 

On request, the NBIC Committee will render an interpretation of any requirement of this Code. 
Interpretations are provided for each Part and are specific to the Code edition and addenda 
referenced in the interpretation. Interpretations provide information only and are not part of 
this Code. 



Jurisdictional Precedence 

Reference is made throughout this Code to the requirements of the "Jurisdiction." Where any 
provision herein presents a direct or implied conflict with any jurisdictional regulation, the 
jurisdictional regulation shall govern. 



Units of Measurement 

Both U.S. customary units and metric units are used in the NBIC. The value stated in U.S. custom- 
ary units or metric units are to be regarded separately as the standard. Within the text, the met- 
ric units are shown in parentheses. In supplement 6, Continued Service and Inspection of DOT 
Transport Tanks, the metric units are shown first with the U.S. customary units shown in parentheses. 

U.S. customary units or metric units may be used with this edition of the NBIC, but one system 
of units shall be used consistently throughout a repair or alteration of pressure-retaining items. 
It is the responsibility of National Board accredited repair organizations to ensure the 
appropriate units are used consistently throughout all phases of work. This includes materials, 
design, procedures, testing, documentation, and stamping. The NBIC policy for metrication is 
outlined in each part of the NBIC. 



Accreditation Programs 

The National Board administers and accredits three specific repair programs 1 as shown below: 

"R" Repairs and Alterations to Pressure-Retaining Items 

"VR" Repairs to Pressure Relief Valves 



1 Caution, some Jurisdictions may independently administer a program of authorization for organizations to perform repairs and 
alterations within that lurisdiction. 



XVI 



NATIONAL BOARD INSPECTION CODE 



"NR" Repair and Replacement Activities for Nuclear Items 

Part 3, Repairs and Alterations, of the NBIC describes the administrative requirements for the 
accreditation of these repair organizations. 

The National Board also administers and accredits four specific inspection agency programs as 
shown below: 

New Construction 

Criteria for Acceptance of Authorized Inspection Agencies for New Construction 
(NB-360) 
Inservice 

Qualifications and Duties for Authorized Inspection Agencies (AlAs) Performing Inservice 
Inspection Activities and Qualifications for Inspectors of Boilers and Pressure Vessels 
(NB-369) 
Owner-User 

Accreditation of Qwner-User Inspection Organizations (OUIO) (NB-371 ) Owners or users 
may be accredited for both a repair and inspection program provided the requirements 
for each accreditation program are met. 
Federal Government 

Qualifications and Duties for Federal Inspection Agencies Performing Inservice Inspection 
Activities (FIAs) (NB-390) 



These programs can be viewed on the National Board Web site. For questions or further infor- 
mation regarding these programs contact: 

The National Board of Boiler and Pressure Vessel Inspectors 

1 055 Crupper Avenue 

Columbus, OH 43229-1 183 

Phone — 614.888.8320 

Fax — 614.847.1828 

Web site — www.nationalboard.org 



Certificates of Authorization for Accreditation Programs 

Any organization seeking an accredited program may apply to the National Board to obtain a 
Certificate of Authorization for the requested scope of activities. A confidential review shall be 
conducted to evaluate the organization's quality system. Upon completion of the evaluation, 
a recommendation will be made to the National Board regarding issuance of a Certificate of 
Authorization. 

Certificate of Authorization scope, issuance, and revisions for National Board accreditation 
programs are specified in the applicable National Board procedures. When the quality system 
requirements of the appropriate accreditation program have been met, a Certificate of 
Authorization and appropriate National Board symbol stamp shall be issued. 



XVI 




Part 2 



Inspection 



All charts, graphs, tables, and other criteria that have been 
reprinted from the ASME Boiler and Pressure Vessel Code, 
Sections I, IV, VIII, and X are used with the permission of 
the American Society of Mechanical Engineers. All Rights 
Reserved. 



NATIONAL BOARD INSPECTION CODE ♦ PART Z — INSPECTION 

PART 2 — INSPECTION 

TABLE OF CONTENTS 

National Board Contact Information II 

NB Board of Trustees /Advisory Committee Members Ill 

National Board Members IV 

NBIC Committee Structure v 

National Board Inspection Code Edition /Addendum XI 

Foreword XII 

Introduction XIV 

Section 1 General Requirements for Inservice Inspection of Pressure-Retaining Items 13 

1.1 Scope 14 

1 .2 Administration 14 

1 .3 Reference to Other Codes and Standards 14 

1 .4 Personnel Safety 14 

1 .4.1 Personal Safety Requirements for Entering Confined Spaces 1 5 

1 .4.2 Equipment Operation 1 6 

1 .5 Inspection Activities 16 

1 .5.1 Inservice Inspection Activities 16 

1 .5.2 Pre4nspection Activities 16 

1.5.3 Preparation for Internal Inspection 16 

1 .5.4 Post4nspection Activities 17 

Section 2 Detailed Requirements for Inservice Inspection of Pressu ^Retaining Items 19 

2.1 Scope 20 

2.2 Boilers 20 

2.2.1 Scope 20 

2.2.2 Service Conditions 20 

2.2.3 Pre4nspection Activities 20 

2.2.4 Condition of Boiler Room or Boiler Location 20 

2.2.5 External Inspection 20 

2.2.6 Internal Inspection 21 

2.2.7 Evidence of Leakage 21 

2.2.8 Boiler Corrosion Considerations 21 

2.2.9 Waterside Deposits 22 

2.2.1 Inspection of Boiler Piping, Parts, and Appurtenances 23 

2.2.10.1 Boiler Piping 23 

2.2.10.2 Stays and Staybolts 23 

2.2.10.3 Flanged or Other Connections 23 

2.2.10.4 Miscellaneous 23 

2.2.10.5 Gages 24 

2.2.10.6 Pressure Relief Devices 24 

2.2.10.7 Controls 24 

2.2.1 1 Records Review 25 

2.2. 1 2 Description and Concerns of Specific Types of Boilers 25 

2.2.12.1 Watertube Boilers 25 

z 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



2.2.12.2 Kraft or Sulfate Black Liquor Recovery Boilers 26 

2.2.12.3 Thermal Fluid Heaters 28 

2.2.12.4 Waste Heat Boilers 30 

2.2.12.5 Cast-iron Boilers 31 

2.2.12.6 Electric Boilers 32 

2.2.12.7 Fired Coil Water Heaters 32 

2.2.12.8 Fired Storage Water Heaters 32 

2.2.12.9 Firetube Boilers 33 

2.3 Pressure Vessels 35 

2.3.1 Scope 35 

2.3.2 Service Conditions 35 

2.3.3 External Inspection 36 

2.3.4 Internal Inspection 37 

2.3.5 Inspection of Pressure Vessel Parts and Appurtenances 38 

2.3.5.1 Cages 38 

2.3.5.2 Safety Devices 38 

2.3.5.3 Controls/Devices 38 

2.3.5.4 Records Review 38 

2.3.6 Description and Concerns of Specific Types of Pressure Vessels 39 

2.3.6.1 Deaerators 39 

2.3.6.2 Compressed Air Vessels 40 

2.3.6.3 Expansion Tanks 40 

2.3.6.4 Liquid Ammonia Vessels 41 

2.3.6.5 Inspection of Pressure Vessels with 

Quick-Actuating Closures 42 

2.4 Piping and Piping Systems 45 

2.4.1 Scope 45 

2.4.2 Service Conditions 45 

2.4.3 Assessment of Piping Design 45 

2.4.4 External Inspection of Piping 45 

2.4.5 Internal Inspection of Piping 46 

2.4.6 Evidence of Leakage 46 

2.4.7 Provisions for Expansion and Support 46 

2.4.8 Inspection of Gages, Safety Devices, and Controls 47 

2.4.8.1 Gages 47 

2.4.8.2 Safety Devices 47 

2.4.8.3 Quick-Disconnect Coupling 47 

2.5 Pressure Relief Devices 47 

2.5.1 Scope 47 

2.5.2 Pressure Relief Device Data 47 

2.5.3 Inservice Inspection Requirements for Pressure Relief Devices 48 

2.5.4 Inservice Inspection Requirements for Pressure Relief Devices 
Installation Condition 48 

2.5.5 Additional Inspection Requirements 49 

2.5.5.1 Boilers 49 

2.5.5.2 Pressure Vessels and Piping 49 

2.5.5.3 Rupture Disks 49 

i.6 Packaging, Shipping and Transportation 51 



j. 

:>./ Testing and Operational Inspection of Pressure Relief Devices ;> i 

5.8 Recommended Inspection and Test Frequencies for 

Pressure Relief Devices 53 



Section 3 Corrosion and Failure Mechanisms 57 

3.1 Scope 58 

3.2 General 58 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



3.3 Corrosion 58 

3.3.1 Macroscopic Corrosion Environments 58 

3.3.2 Microscopic Corrosion Environments 59 

3.3.3 Control of Corrosion 60 

3.3.3.1 Process Variables 60 

3.3.3.2 Protection 60 

3.3.3.3 Material Selection 60 

3.3.3.4 Coatings 61 

3.3.3.5 Engineering Design 61 

3.3.3.6 Conclusion 61 

3.4 Failure; Mechanisms 62 

3.4.1 Fatigue 62 

3.4.2 Creep 62 

3.4.3 Temperature Effects 62 

3.4.4 I lydrogen Embrittlcmcnt 62 

3.4.5 High Temperature Hydrogen Attack 63 

3.4.6 Hydrogen Damage 64 

3.4.7 Bulges and Blisters 64 

3.4.8 Overheating 64 

3.4.9 Cracks 65 

Section 4 Examinations, Test Methods, and Evaluations 67 

4.1 Scope 68 

4.2 Nondestructive Examination Methods (NDE) 68 

4.2.1 Visual 68 

4.2.2 Magnetic Particle 68 

4.2.3 Liquid Penetrant 69 

4.2.4 Ultrasonic 69 

4.2.5 Radiography 69 

4.2.6 Eddy Current 70 

4.2.7 Metal lographic 70 

4.2.8 Acoustic Emission 70 

4.3 Testing Methods 71 

4.3.1 Pressure Testing 71 

4.3.2 Leak Testing 71 

4.3.3 Evidence of Leakage in a Boiler 71 

4.4 Methods to Assess Damage Mechanisms and Inspection Frequency 

for Pressure-Retaining Items 72 

4.4.1 Scope 72 

4.4.2 General Requirements 73 

4.4.3 Responsiblities 73 

4.4.4 Remaining Service Life Assessment Methodology 73 

4.4.5 Data Requirements for Remaining Service Life Assessments 74 

4.4.6 Identification of Damage Mechanisms 75 

4.4.7 Determining Inspection Intervals 75 

4.4.7.1 Method for Estimating Inspection Intervals for 
Pressure-Retaining Items Subject to Erosion 

or Corrosion 75 

4.4.7.2 Method for Estimating Inspection Intervals 

for Exposure to Corrosion 76 

4.4.7.3 Estimating Inspection Intervals for Pressure-Retaining 
Items Where Corrosion Is Not a Factor 79 

4.4.8 Evaluating Inspection Intervals of Pressure-Retaining Items 

Exposed to Inservice Failure Mechanisms 79 

4.4.8.1 Exposure to Elevated Temperature (Creep) 79 



NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



4.4.8.2 Exposure to Brittle Fracture 80 

4.4.8.3 Evaluating Conditions That Cause 

Bulges/Blisters/I. animations 80 

4.4.8.4 Evaluating Crack-Like Indications in Pressure- 
Retaining Items 80 

4.4.8.5 Evaluating Exposure of a Pressure-Retaining Item to 

Fire Damage 81 

4.4.8.6 Evaluating Exposure of Pressure-Retaining Items to 

Cyclic Fatigue 82 

4.4.8.7 Evaluating Pressure-Retaining Items Containing Local 

Thin Areas 82 

4.5 Risk-Based Inspection Assessment Programs 83 

4.5.1 Scope 83 

4.5.2 Definitions 83 

4.5.3 General 83 

4.5.4 Considerations 84 

4.5.5 Key Elements of an RBI Assessment Program 84 

4.5.6 RBI Assessment 85 

4.5.6.1 Probability of Failure 85 

4.5.6.2 Consequence of Failure 85 

4.5.6.3 Risk Evaluation 85 

4.5.6.4 Risk Management 86 

4.5.7 Jurisdictional Relationships 86 

Section 5 Stamping, Documentation, and Forms 87 

5.1 Scope 88 

5.2 Replacement of Stamping During Inservice Inspection 88 

5.2.1 Authorization 88 

5.2.2 Replacement of Stamped Data 88 

5.2.3 Reporting 88 

5.3 National Board Inspection Forms 88 

5.3.1 Scope 88 

5.3.2 Replacement of Stamped Data Form (NB-136) 89 

5.3.3 New Business or Discontinuance of Business Form (NB-4) 91 

5.3.4 Boiler or Pressure Vessel Data Report Form (NB-5) 93 

5.3.5 Boiler-Fired Pressure Vessels Report of Inspection Form (NB-6) 95 

5.3.6 Pressure Vessels Report of Inspection Form (NB-7) 97 

5.3.7 Report of Fitness For Service Assessment Form (NB-403) 99 

5.3.7.1 Guide For Completing Fitness For Service 

Assessment Reports 101 

Section 6 Supplements 103 

6.1 Scope 104 

Supp. 1 Steam Locomotive Firetube Boiler Inspection and Storage 104 

51.1 Scope 104 

51.2 Special Jurisdictional Requirements 104 

51.3 Federal Railroad Administration (FRA) 105 

51.4 Locomotive Firetube Boiler Inspection 105 

51.4.1 Inspection Methods 105 

51.4.2 Inspection Zones 106 

51 .4.2.1 Riveted Seams and Rivet Heads 106 

51 .4.2.2 Welded and Riveted Repairs 106 

51.4.2.3 Boiler Shell Course 107 

51.4.2.4 Dome and Dome Lid 107 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



SI .4.2.5 Mudring 107 

S1.4.2.6 Flue Sheets 107 

SI .4.2.7 Flanged Sheets 108 

SI .4.2.8 Stayed Sheets 108 

SI .4.2.9 Staybolts 108 

S1 .4.2.10 Flexible Staybolts and Sleeves 109 

SI .4.2.1 1 Girder Stay and Crown Bars 110 

SI .4.2.1 2 Sling Stays 110 

SI .4.2.1 3 Crown Stays and Expansion Stays 1 1 1 

SI .4.2.14 Diagonal and Gusset Braces 1 1 1 

51. 4.2. 15 Flues 112 

51 .4.2.16 Superheater Units and Header 1 12 

SI .4.2.1 7 Arch Tubes, Water Bar Tubes, and Circulators 112 

51 .4.2.18 Thermic Syphons 1 13 

51. 4. 2. 19 Firebox Refractory 113 

51.4.2.20 Dry Pipe 113 

51 .4.2.21 Throttle and Throttle Valve 113 

51 .4.2.22 Screw-Type Washout Plugs, Holes, and Sleeves 114 

51.4.2.23 Handhole Washout Doors 114 

51 .4.2.24 Threaded and Welded Attachment Studs 114 

51 .4.2.25 Fusible Plugs 115 

51 .4.2.26 Water Glass, Water Column, and Gage Cocks 115 

51 .4.2.27 Steam Pressure Gage 115 

51 .4.2.28 Boiler Fittings and Piping 115 

51.4.2.29 Boiler Attachment Brackets 116 

51. 4.2. 30 Fire Door 116 

51. 4. 2. 31 Grates and Grate Operating Mechanism 116 

51.4.2.32 Smokebox 116 

51 .4.2.33 Smokebox Steam Pipes 1 1 7 

51 .4.2.34 Ash Pan and Fire Pan 1 1 7 

S1 .5 Guidelines for Steam Locomotive Storage 1 1 7 

SI .5.1 Storage Methods 1 1 7 

51.5.2 Wet Storage Method 118 

51.5.3 Dry Storage Method 118 

51.5.4 Recommended General Preservation Procedures 119 

51.5.5 Use of Compressed Air to Drain Locomotive Components 122 

51 .5.6 Return to Service 122 

Supp. 2 Historical Boilers 124 

52.1 Scope 124 

52.2 Introduction 124 

52.3 Responsibilities 124 

52.4 General Inspection Requirements 124 

52.4.1 Pre-lnspection Requirements 124 

52.4.2 Post-Inspection Activities 125 

52.4.3 Boiler Operators 125 

52.4.4 Examinations andTests 126 

52.4.4.1 Nondestructive Examination Methods 126 

52.4.4.2 Testing Methods 126 

52.5 Specific Examination andTest Methods 126 

52.5.1 Specific Examination Methods 126 

52.5.2 Visual Examination 126 

52.5.2.1 Preparation for Visual Inspection 126 

52.5.2.2 Visual Examination Requirements 127 

52.5.3 Ultrasonic Examination 127 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



52.5.4 Liquid Penetrant Examination 127 

52.5.5 Magnetic Particle Examination 127 

52.6 Specific Testing Methods 127 

52.6.1 Hydrostatic Pressure Testing 127 

52.6.2 Ultrasonic Thickness Testing 128 

52.7 Inspections 128 

52.7.1 Inservice Inspections 128 

52.7.2 Inservice Inspection Documentation 129 

52.7.3 Inspection Intervals 129 

52.7.3.1 Initial Inspection 129 

52.7.3.2 Subsequent Inspections 129 

52.8 Safety Devices — General Requirements 1 30 

52.8.1 Safety Valves 130 

52.8.2 Cage Class 131 

52.8.3 Try-Cocks 131 

52.8.4 Fusible Plug 131 

52.8.5 Pressure Cage 131 

52.9 Appurtenances - Piping, Fittings, and Valves 132 

S2.9.1 Piping, Fittings, andValve Replacements 132 

52.10 Maximum Allowable Working Pressure (MAWP) 132 

52.10.1 Strength '. 132 

52.10.2 Rivets 133 

52.10.3 Cylindrical Components 133 

52.10.4 Stayed Surfaces 140 

S2. 10.4.1 Staybolts 140 

52.10.5 Construction Code 140 

52.10.6 Nomenclature 140 

52.10.7 Limitations 143 

52.1 1 Boiler Inspection Guideline 143 

52.12 Initial Boiler Certification Report Form 148 

52.13 Guidelines for Historical Boiler Storage 148 

52.13.1 Storage Methods 148 

52.13.1.1 Wet Storage Method 148 

52.13.1.2 Dry Storage Method 149 

52.13.2 Recommended General Preservation Procedures 150 

52.1 3.3 Use of Compressed Air to Drain Historical Boiler Components 1 52 

52.13.4 Return to Service 152 

52.14 Safely Procedures 153 

52.14.1 Experience 153 

52.14.2 Stopping Engine in an Emergency 154 

52.14.3 Water Glass Breakage 154 

52.14.4 Runaway Engine and Governor Over Speed 155 

52.14.5 Killing a Fire 155 

52.14.6 Injector Problems 155 

52.14.7 Foaming or Priming Boiler 157 

52.14.8 Handhole Gasket Blows Out 157 

52.14.9 Tube Burst 158 

52. 14. 10 Leaking Valves 158 

52.14.11 Broken Pipes 158 

52.14.12 Safety Valve Problems 158 

52.14.13 Safety Valve Opens but will not Close 158 

52.14.14 Leaking Pipe Plugs 159 

52.14.15 Melted Grates 159 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Supp. 3 Inspection of Graphite Pressure Equipment 1 63 

53.1 Scope 163 

53. 2 Application 163 

53. 3 Operations 163 

53. 4 Inservice Inspection 163 

Supp. 4 Inspection of Fiber-Reinforced Thermosetting Plastic Pressure Equipment 1 65 

54.1 Scope 165 

54.2 Inservice Inspection 165 

54.3 General 165 

54.4 Visual Examination 165 

54.5 Inspector Qualifications 166 

54.6 Assessment of Installation 166 

54.6.1 Preparation 166 

54.6.2 Leakage 167 

54.6.3 Tools 167 

54.7 External Inspection 167 

54.7.1 Insulation or Other Coverings 167 

54.7.2 Exposed Surfaces 167 

54.7.3 Structural Attachments 168 

54.8 Internal Inspection 168 

54.8.1 General 168 

54.8.2 Specific Areas of Concern 1 68 

54.9 Inspection Frequency 168 

54.9.1 Newly Installed Equipment 169 

54.9.2 Previously Repaired or Altered Equipment 169 

S4.10 Photographs of Typical Conditions 1 70 

Supp. 5 Inspection of Yankee Dryers (Rotating Cast-iron Pressure Vessels) with 

Finished Shell Outer Surfaces 186 

55.1 Scope 186 

55.2 Assessment of Installation 186 

55.2.1 Determination of Allowable Operating Parameters 188 

53. 2. 2 Adjusting the Maximum Allowable Operating Parameters of 
the Yankee Dryer Due to a Reduction in Shell Thickness from 
Grinding or Machining 189 

55.2.3 Documentation of Shell Thickness and Adjusted Maximum 
Allowable Operating Parameters 190 

55.3 Causes of Deterioration and Damage 190 

55.3.1 Local Thinning 190 

55.3.2 Cracking 191 

55.3.2.1 Through Joints and Bolted Connections 1 91 

55.3.2.2 Through-Wall Leakage 191 

55.3.2.3 Impact From Objects Passing Through The Yankee/ 
Pressure Roll Nip 192 

55.3.2.4 Stress Magnification Around Drilled Holes 192 

55.3.2.5 Thermal Stress and/or Micro-Structural Change From 
Excessive Local Healing and Cooling 192 

55.3.2.6 Joint Interface Corrosion 192 

55.3.2.7 Stress-Corrosion Cracking of Structural Bolts 193 

55.3.3 Corrosion 193 

55.4 Inspections 193 

55.5 Nondestructive Examination 193 

55.6 Pressure Testing 194 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Supp. 6 Continued Service and Inspection of DOT Transport Tanks 195 

56.1 Scope 195 

56.2 Terminology 195 

56.3 Administration 195 

56.4 Inspection 195 

56.4.1 Scope 195 

56.4.2 General Requirements for Inspectors 195 

56.4.3 Registration of Inspectors 196 

56.4.4 Qualifications of Inspectors 196 

56.4.5 Codes of Construction 196 

56.4.6 Inspector Duties for Continued Service Inspections 1 96 

56.4.6.1 Inspector Duties for Continued Service Inspection 

of Cargo Tanks 197 

56.4.6.2 Inspector Duties for Continued Service Inspection 

of PortableTanks 197 

56.4.6.3 Inspector Duties for Continued Service Inspections 

of Ton Tanks 198 

56.4.7 Continued Service, Inspection for DOT Transport Tanks Scope 198 

56.4.7.1 Administration 198 

56.4.7.2 Inspection and Test Required Frequencies 1 98 

56.4.7.3 External Visual and Pressure Tests 198 

56.4.7.4 Leak Tightness Testing of Transport Tanks 198 

56.4.7.4.1 Cargo Tanks 198 

56.4. 7.4.2 PortableTanks 199 

56.4. 7.4.3 Ton Tanks 199 

56.4.7.4.4 Leak Tightness Testing of Valves 199 

56.4.7.4.4.1 Cargo Tanks 199 

56. 4. 7.4.4.2 PortableTanks 199 

56. 4. 7.4.4.3 Ton Tanks 200 

56.4.7.5 Leak Tightness Testing of Safety Relief Devices 200 

56.4.7.5.1 Cargo Tanks 200 

56.4.7.5.2 PortableTanks 200 

56.4.7.5.3 Ton Tanks 201 

56.4.7.6 Testing of Miscellaneous Pressure Parts 201 

56.4.7.6.1 Cargo Tanks 201 

56.4.7.6.2 Portable Tank 201 

56.4.7.6.3 Ton Tanks 201 

56.4.7.7 Acceptance Criteria 201 

56.4.7.8 Inspection Report 202 

56.4. 7.8.1 Cargo Tanks 202 

56.4.7.8.2 PortableTanks 202 

56.4.7.8.3 Ton Tanks 202 

56.5 Stamping and Record Requirements for DOT Transport Tanks in 

Continued Service 202 

56.5.1 General 202 

56.5.2 Stamping 202 

56.5.3 Owner or User Required Records For Cargo Tanks 203 

56.5.3.1 Reporting Requirements by the Owner or User of 
Tests and Inspections of DOT Specification 

Cargo Tanks 205 

56.5.3.2 DOT Marking Requirements for Test and Inspections 

of DOT Specification Cargo Tanks 205 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



56.5.4 Owner or User Required Records for Portable Tanks 205 

56.5.4.1 Reporting of Periodic and Intermediate Periodic 
Inspection and Tests of DOT Specification 

Portable Tanks 206 

56. 5.4.2 Marking Requirements for Periodic and Intermediate 
Inspection and Test for IM or UN Portable Tanks 206 

56.5.4.3 DOT Marking Requirements for Periodic and 
Intermediate Inspection and Tests of DOT 
Specification 51, 56, 57, or 60 Portable Tanks 206 

56.5.5 Owner or User Required Reports for DOT Specification 1 06A 

and DOT 1 10A Ton Tanks 207 

56.5.5.1 Reporting of Inspection and Tests for DOT 
Specification 106Aand DOT 110A Ton Tanks 207 

56.5.5.2 DOT Marking Requirements for Test and Inspection 

of DOT Specification 106Aand 110A Ton Tanks 207 

56.6 Corrosion and Failure Mechanisms in Transport Tanks 208 

56.6.1 Scope 208 

56.6.2 General 208 

56.6.3 Internal and/or External Corrosion 208 

S6.6.3.1 Types of Corrosion 208 

56.6.4 Failure Mechanisms 210 

56.7 Classification Boundaries 212 

56.8 Pressure, Temperature, and Capacity Requirements for Transport Tanks 212 

56.9 Reference to Other Codes and Standards 212 

56.10 Conclusion 213 

56.1 1 Personnel Safety and Inspection Activities 213 

56.12 Transport Tank Entry Requirements 214 

56.12.1 Pre4nspection Activities 214 

56.12.2 Preparation for Internal Inspection 215 

56.12.3 Post4nspection Activities 216 

56.13 Inspection andTests of Cargo Tanks 216 

56.13.1 Visual External Inspection 216 

56.13.2 Inspection of Piping, Valves, and Manholes 219 

56.13.3 Inspection of Appurtenances and Structural Attachments 220 

56.13.4 Visual Internal Inspection 221 

56.13.5 Lining Inspections 221 

56.13.6 Pressure Tests 223 

56.13.6.1 Hydrostatic or Pneumatic Test Method 224 

56.1 3.6.2 Pressure Testing Insulated Cargo Tanks 225 

56.1 3.6.3 Pressure Testing Cargo Tanks Constructed of 

Quenched and Tempered Steels 225 

56.13.6.4 Pressure Testing Cargo Tanks Equipped with a 

Heating System 226 

56.13.6.5 Exceptions to Pressure Testing 226 

56. 13.6.6 Acceptance Criteria 226 

56.13.6.7 Inspection Report 226 

56.13.7 Additional Requirements for MC 330 and MC 331 Cargo Tanks 227 

56.13.8 Certificates and Reports 228 

56.13.9 Leakage Test 228 

56.13.10 New or Replaced Delivery Hose Assemblies 231 

56.13.10.1 Thickness Testing 231 

56. 13. 10.2 Testing Criteria 231 

56. 13. 10.3 Thickness Requirements 232 



i □ 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S6.13.1 1 Cargo Tanks That No Longer Conform to the Minimum Thickness 

Requirements in Tables S6.1 3.1 -a and S6.1 3.1 -b 232 

56.13.1 1.1 Minimum Thickness for 400 Series Cargo Tanks 233 

56.1 3.1 1.2 DOT 406 Cargo Tanks 233 

56.13.11.3 DOT 407 Cargo Tanks 234 

56.13.11.4 DOT 412 Cargo Tanks 235 

56.14 Inspection andTests of PortableTanks 239 

56.14.1 Periodic Inspection andTest 240 

56.14.2 Intermediate Periodic Inspection and Test 240 

56.14.3 Internal and External Inspections 240 

56.14.4 Exceptional Inspection andTest 241 

56.14.5 Internal and External Inspection Procedure 241 

56.14.6 Pressure Tests Procedures for Specification 51, 57, 60, IM or UN 
PortableTanks 242 

56.14.6.1 Specification 57 PortableTanks 242 

56.14.6.2 Specification 51 or 56 PortableTanks 243 

56.14.6.3 Specification 60 PortableTanks 244 

56.14.6.4 Specification IM or UN PortableTanks 244 

56.14.7 Inspection andTest Markings for IM or UN PortableTanks 245 

56.14.8 Inspection andTest Markings for Specification DOT 51, 56, 

57, or 60 246 

56.14.9 Record Retention 246 

56.1 5 General Requirements for DOT Specification 1 06A and 1 1 0A Tank 

Cars (Ton Tanks) 246 

56.1 5.1 Special Provisions for Ton Tanks 247 

56.15.2 Visual Inspection of Ton Tanks 249 

56.1 5.3 Inspection and Tests of DOT Specification 1 06A and 

DOT Specification 110A Ton Tanks 249 

S6.1 5.3.1 Air Tests 250 

S6.1 5.3.2 Pressure Relief Device Testing 250 

S6.1 5.3.3 Rupture Discs and Fusible Plugs 250 

S6.1 5.3.4 Successful Completion of the Periodic Retesting 250 

56. 15.3.5 Exemptions to Periodic Hydrostatic Retesting 251 

S6.1 5.3.6 Record of Retest Inspection 251 

56.15.4 Stamping Requirements of DOT 106Aand DOT 110A Ton Tanks ...251 

56.16 Definitions 252 

Supp.7 Inspection of Pressure Vessels in Liquefied Petroleum Gas (LPG) Service 259 

57.1 Scope 259 

57.2 Pre4nspection Activities 259 

57.3 Inservice Inspection for Vessels in LP Gas Service 259 

S7.3.1 Nondestructive Examination (NDE) 259 

57.4 External Inspection 260 

57.5 Internal Inspection 260 

57.6 Leaks 260 

57.7 Fire Damage 260 

57.8 Acceptance Criteria 261 

57.8.1 Cracks 261 

57.8.2 Dents 261 

57.8.3 Bulges 262 

57.8.4 Cuts or Gouges 262 

57.8.5 Corrosion 262 



i i 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Section 7 NIBIC Policy tor Metrication 263 

7.1 General 264 

7.2 Fquivalent Rationale 264 

7.3 Procedure for Conversion 264 

7.4 Referencing Tables 265 

Section 8 Preparation of Technical Inquiries to the National Board Inspection Code 

Committee 269 

8.1 Introduction 270 

8.2 Inquiry Format 270 

8.3 Code Revisions or Additions 271 

8.4 Code Interpretations 271 

8.5 Submittals 271 

Section 9 Glossary of Terms 273 

9.1 Definitions 274 



Section 10 KBIC Approved Interpretations 



> 



/, 



10.1 Scope 278 

10.2 Index of Interpretations 278 

1 0.3 Subject Index of Interpretations 282 



Section 1 1 Index 285 



1 2 




Part 2, Section l 

Inspection — General Requirements 
For Inservice Inspection of 
Pressure-Retaining Items 



1 3 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



PART 2, SECTION 1 

INSPECTION — GENERAL REQUIREMENTS FOR INSERVICE 

INSPECTION OF PRESSURE-RETAINING ITEMS 



1.1 



SCOPE 



This section provides general guidelines and 
requirements for conducting inservice inspec- 
tion of pressure-retaining items. Appropriately, 
this Section includes precautions for the safety 
A07 of inspection personnel. The safety of the public 
and the Inspector is the most important aspect 
of any inspection activity. 



1.2 



ADMINISTRATION 



Jurisdictional requirements describe the fre- 
quency, scope, type of inspection, whether 
internal, external, or both, and type of docu- 
mentation required for the inspection. The 
Inspector shall have a thorough knowledge 
of jurisdictional regulations where the item is 
installed, as jurisdictional or regulatory inspec- 
tion requirements do vary. 



1.3 REFERENCE TO OTHER CODES 

AND STANDARDS 

Other existing inspection codes, standards, and 
practices pertaining to the inservice inspection 
of pressure-retaining items can provide use- 
ful information and references relative to the 
inspection techniques listed in this Part. Some 
examples are as follows: 



National Board Bulletin 
Classic Articles Series 



National Board 



b) American Society of Mechanical Engineers 

— ASME Boiler and Pressure Vessel Code 
Section V (Nondestructive Examination) 

c) American Society of Mechanical Engineers 

— ASME Boiler and Pressure Vessel Code 
Section VI (Recommended Rules for the 
Care and Operation of Heating Boilers) 



d) American Society of Mechanical Fngineers 

— ASME Boiler and Pressure Vessel Code 
Section VII (Recommended Guidelines for 
the Care of Power Boilers) 

e) American Society of Mechanical Engineers 

— ASME B31G (Manual for Determining 
the Remaining Strength of Corroded Pipe- 
lines) 

I) American Petroleum Institute — API 572, 
Inspection of Pressure Vessels 

g) American Petroleum Institute — API 574, 
Inspection Practices for Piping System 
Components 

h) American Petroleum Institute — API 579 
Fitness-For-Service 

i) ASME CRTD Volume 41 , Risk-Based Inspec- A07 
tion for Equipment Life Management: 
Application Handbook 



An 



j) API Recommended Practice 580, Risk- A07 
Based Inspection 

k) API Publication 581 , Base Resource Docu- A07 
ment on Risk-Based Inspection 



1.4 PERSONNEL SAFETY 

a) Personnel safety is the joint responsibility 
of the owner or user and the Inspector. All 
applicable safety regulations shall be fol- 
lowed. This includes federal, state, regional, 
and/or local rules and regulations. Owner 
or user programs, safety programs of the 
Inspector's employer, or similar standards 
also apply. In the absence of such rules, 
prudent and generally accepted engineer- 



1 4 



NATIONAL BDARD INSPECTION CODE • PART Z — INSPECTION 



ing safety procedures satisfactory to the 
Inspector shall be employed by the owner 
or user. 

b) Inspectors are cautioned that the operation 
of safety devices involve the discharge of 
fluids, gases, or vapors. Extreme caution 
should be used when working around 
these devices due to hazards to personnel. 
Suitable hearing protection should be used 
during testing because extremely high noise 
levels can damage hearing. 

c) Inspectors shall take all safety precautions 
when examining equipment. Proper per- 
sonal protective equipment shall be worn, 
equipment shall be locked out, blanked off, 
decontaminated, and confined space entry 
permits obtained before internal inspec- 
tions are conducted. In addition, inspectors 
shall comply with plant safety rules associ- 
ated with the equipment and area in which 
they are inspecting. Inspectors are also 
cautioned that a thorough decontamination 
of the interior of vessels is sometimes very 
hard to obtain and proper safety precau- 
tions must be followed to prevent contact 
or inhalation injury with any extraneous 
substance that may remain in the tank or 
vessel. 



1.4.1 PERSONAL SAFETY 

REQUIREMENTS FOR ENTERING 
CONFINED SPACES 

a) No pressure-retaining item shall be entered 
until it has been properly prepared for in- 
spection. The owner or user and Inspector 
shall jointly determine that pressure-retain- 
ing items may be entered safely. This shall 
include: 

A07 1 ) Recognized hazards associated with en- 
try into the object have been identified 
by the owner or user and are brought 
to the attention of the Inspector, along 
with acceptable means or methods for 
eliminating or minimizing each of the 
hazards; 



2) Coordination of entry into the object 
by the Inspector and owner or user 
representalive(s) working in or near the 
object; 

3) Personal protective equipment required 

to enter an object shall be used. This A07 
may include, among other items, pro- 
tective outer clothing, gloves, respira- 
tory protection, eye protection, foot 
protection, and safety harnesses. The 
Inspector shall have the proper training 
governing the selection and use of any 
personal protective clothing and equip- 
ment necessary to safely perform each 
inspection. Particular attention shall be 
afforded respiratory protection if the 
testing of the atmosphere of the object 
reveals any hazards; 

4) Completing and posting of confined A07 
space entry permits, as applicable; 
and 

5) An effective energy isolation program 
(lock out and/or tag out) is in place and 
in effect that will prevent the unex- 
pected energizing, start up, or release 
of stored energy. 

b) The Inspector shall determine that a safe 
atmosphere exists before entering the pres- 
sure-retaining item. The atmosphere shall 
be verified by the owner or user as directed 
by the Inspector. 

1 ) The oxygen content of the breathable 
atmosphere shall be between 19.5% 
and 23.5%. 

2) If any flammable or combustible materi- 
als are present in the atmosphere they 
shall not exceed 10% of their lower ex- 
plosive limit (LED or lower flammable 
limit (LFL). 

3) The Inspector shall not enter an area if 
toxic, flammable or inert gases, vapors 
or dusts are present and above accept- 
able limits. 



i 5 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



1.4.2 



EQUIPMENT OPERATION 



The Inspector shall not operate owner or user 
equipment. Operation shall be conducted only 
by competent owner or user employees familiar 
with the equipment and qualified to perform 
such tasks. 



2) Current jurisdictional inspection certifi- 
cate; 

3) ASME Code Symbol Stamping or mark 
of code of construction; 

4) National Board and/or jurisdiction reg- 
istration number; 



1.5 



INSPECTION ACTIVITIES 



A proper inspection of a pressure-retaining 
item requires many pro-inspection planning 
activities including: safety considerations, an 
inspection plan that considers the potential 
damage mechanisms, selection of appropri- 
ate inspection methods, and awareness of 
the jurisdictional requirements. This section 
describes pre-inspection and post-inspection 
activities applicable to all pressure-retaining 
items. Specific inspection requirements for 
pressure-retaining items are identified in 2.2 for 
Boilers, 2.3 for Pressure Vessels, 2.4 for Piping 
and Piping Systems, and 2.5 for Pressure Relief 
Devices. 



1.5.1 INSERVICE INSPECTION 

ACTIVITIES 

Any defect or deficiency in the condition, op- 
erating, and maintenance practices of a boiler, 
pressure vessel, piping system, and pressure 
relief devices noted by the Inspector shall be 
discussed with the owner or user at the time 
of inspection and recommendations made for 
the correction of such defect or deficiency shall 
be documented. Use of a checklist to perform 
inservice inspections is recommended. 



5) Operating conditions and normal con- 
tents of the vessel (discuss any unique 
hazards with the owner or user); 

6) Previous inspection report, operat- 
ing/maintenance logs and test records, A07 
and any outstanding recommendations 
from the previous inspection; 

7) Records of wall thickness checks, es- 
pecially where corrosion or erosion is 
a consideration; 

8) Review of repairs or alterations and any 
associated records for compliance with 
applicable requirements; and 

9) Observation of the condition of the A07 
overall complete installation, including 
maintenance and operation records. 

b) The following activities should be consid- 
ered to support the inspection: 

1) Removal of pressure gages or other 
devices for testing and calibration. 

2) Accessibility to inspect and test each A07 
pressure-retaining item and its appur- 
tenances. 



1.5.2 



PRE-INSPECTION ACTIVITIES 



a) Prior to conducting the inspection, a review 
of the known history of the pressure-retain- 
ing item and a general assessment of current 
conditions shall be performed. This shall 
include a review of information such as: 

1 ) Date of last inspection; 



1.5.3 PREPARATION FOR INTERNAL 

INSPECTION 

The owner or user has the responsibility to 
prepare a pressure-retaining item for internal 
inspection. Requirements of occupational 
safety and health regulations (federal, state, 
local, or other), as well as the owner-user's 
own program and the safety program of the 



i e 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Inspector's employer are applicable. The pres- 
sure-retaining item should be prepared in the 
following manner or as deemed necessary by 
the Inspector: 

a) When a vessel is connected to a common 
header with other vessels or in a system 
where liquids or gases are present, the 
vessel shall be isolated by closing, locking, 
and/or tagging stop valves in accordance 
with the owner's or user's procedures. When 
toxic or flammable materials are involved, 
additional safety precautions may require 
removing pipe sections or blanking pipe- 
lines before entering the vessel. The means 
of isolating the vessel shall be in compli- 
ance with applicable occupational safety 
and health regulations and procedures. For 
boilers or fired pressure vessels, the fuel 
supply and ignition system shall be locked 
out and/or tagged out, in accordance with 
the owner's or user's procedures. 

b) The vessel temperature shall be allowed to 
cool or warm at a rate to avoid damage to 
the vessel. When a boiler is being prepared 
for internal inspection, the water should not 
be withdrawn until it has been sufficiently 
cooled at a rate to avoid damage. 

c) The vessel shall be drained of all liquid 
and shall be purged of any toxic or flam- 
mable gases or other contaminants that 

A07 were contained in the vessel. The continu- 
ous use of mechanical ventilation using a 
fresh air blower or fan may be necessary 
to maintain the vessel's atmosphere within 
acceptable limits. During air purging and 
ventilation of vessels containing flammable 
gases, the concentration of vapor in air may 
pass through the flammable range before a 
safe atmosphere is obtained. All necessary 
precautions shall be taken to eliminate the 
possibility of explosion or fire. 

A07 d) Items requested by the Inspector, such as 
manhole and hand hole plates, washout 
plugs, inspection plugs, and any other items 
shall be removed. 



e) The Inspector shall not enter a vessel until 
all safety precautions have been taken. 
The temperature of the vessel shall be such 
that the inspecting personnel will not be 
exposed to excessive heat. Vessel surfaces 
should be cleaned as necessary so as to 
preclude entrant exposure to any toxic or 
hazardous materials. 

f) If requested by the Inspector or required 
by regulation or procedure, a responsible 
attendant shall remain outside the vessel 
at the point of entry while the Inspector is 
inside and shall monitor activity inside and 
outside and communicate with the Inspec- 
tor as necessary. The attendant shall have a 
means of summoning rescue assistance, if 
needed, and to facilitate rescue procedures 
lor all entrants without personally entering 
the vessel. 

Note: If a vessel has not been properly pre- 
pared for an internal inspection, the Inspec- 
tor shall decline to make the inspection. 



1.5.4 POST-tNSPECTfON ACTIVITIES 

a) During any inspections or tests of pressure- 
retaining items, the actual operating and 
maintenance practices should be noted by 
the Inspector and a determination made as 
to their acceptability. 

b) Any defects or deficiencies in the condition, 
operating, and maintenance practices of the 
pressure-retaining item shall be discussed 
with the owner or user at the time of in- 
spection and recommendations made for 
correction, hollow-up inspections should A07 
be performed as needed to determine if 
deficiencies have been corrected satisfac- 
torily. 

c) Documentation of inspection shall contain 
pertinent data such as description of item, 
classification, identification numbers, in- 
spection intervals, date inspected, type of 
inspection, and test performed, and any 



l v 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



other information required by the inspec- 
tion agency, jurisdiction, and/or owner-user. 
The Inspector shall sign, date, and note any 
deficiencies, comments, or recommenda- 
tions on the inspection report. The Inspector 
should retain and distribute copies of the 
inspection report, as required. 

A07 d) The form and format of the inspection 
report shall be as required by the Jurisdic- 
tion. Where no Jurisdiction exists, forms 
NB-5, NB-6, or NB-7 (see 5.3) or any other 
form(s) required by the inspection agency or 
owner-user may be used as appropriate. 



1 B 




ipapi^^MBiiifc. i^^^b 







Part 2, Section 2 

Inspection — Detailed Requirements 
For Inservice Inspection of 
Pressure-Retaining Items 



1 9 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



PART 2, SECTION 2 

INSPECTION — DETAILED REQUIREMENTS FOR 

1NSERVICE INSPECTION OF PRESSURE-RETAINING ITEMS 



2.1 SCOPE 

A07 a) This section describes general and detailed 
inspection requirements for pressure- 
retaining items to determine corrosion 
deterioration and possible prevention of 
failures for boilers, pressure vessels, piping, 
and pressure relief devices. 

b) Materials to be inspected shall be suitably 
prepared so surface irregularities will not be 
confused with or mask any defects. Material 
conditioning such as cleaning, buffing, wire 
brushing, or grinding may be required by 
procedure or, if requested, by the Inspec- 
tor. The Inspector may require insulation or 
component parts to be removed. 



2.2 BOILERS 



often be used by the Inspector as a guide 
in forming an opinion of the care given to 
the boiler. 

Usually the conditions to be observed by 
the Inspector are common to both power 
and heating boilers; however, where ap- 
propriate, the differences are noted. 



2.2.3 



PRE-INSPECTION ACTIVITIES 



A review of the known history of the boiler shall 
be performed. This shall include a review of 
information contained in 1 .5.2 and other items 
listed in 2.2.4 below. 



2.2.4 CONDITION OF BOILER ROOM 

OR BOILER LOCATION 



2.2.1 



SCOPE 



This section provides guidelines for external 
and internal inspection of boilers used to con- 
tain pressure. This pressure may be obtained 
from an external source or by the application 
of heat from a direct or indirect source or a 
combination thereof. 



The general condition of the boiler room or 
boiler location should be assessed using ap- 
propriate jurisdictional requirements and 
overall engineering practice. Items that are 
usually considered are lighting, adequacy of 
ventilation for habitability, combustion air, 
housekeeping, personal safety, and general 
safety considerations. 



2.2.5 



EXTERNAL INSPECTION 



2.2.2 



SERVICE CONDITIONS 



a) Boilers are designed for a variety of service 
conditions. The temperature and pressure at 
which they operate should be considered 
in establishing inspection criteria. This part 
is provided for guidance of a general na- 
ture. There may be occasions where more 
detailed procedures will be required. 

b) The condition of the complete installation, 
including maintenance and operation, can 



The external inspection of a boiler is made to 
determine if it is in a condition to operate safely. 
Some items to consider are: 

a) The boiler fittings, valves, and piping should 
be checked for compliance with ASME 
Code or other standards or equivalent re- 
quirements. Particular attention should be A07 
paid to pressure relief devices and other 
safety controls; 



2D 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



A07 b) Firing equipment controls; 

c) Adequacy of structure, boiler supports, and 
any associated support steel; 

d) Boiler casing should be free from cracks, 
combustion gas, or fluid leaks, excessive 
corrosion or other degradation that could 
interfere with proper operation; 

e) Soot blowers, valves, and actuating mecha- 
nisms; 

f) Gaskets on observation doors, access doors, 
drums, handhole and manhole covers and 
caps; 

g) Valves and actuators, either chains, motors, 
and/or handwheels; and 

h) Leakage of fluids or combustion gases. 



2.2.6 



INTERNAL INSPECTION 



a) When a boiler is to be prepared for internal 
inspection, the water shall not be with- 
drawn until the setting has been sufficiently 
cooled at a rate to avoid damage to the 
boiler as well as additional preparations 
identified in 1.4.1 and 1.5.3. 

b) The owner or user shall prepare a boiler for 
internal inspection in the following man- 
ner: 

1) Before opening the manhole(s) and 
entering any part of the boiler that is 
connected to a common header with 
other boilers, the required steam or 
water system stop valves (including 
bypass) must be closed, locked out, 
and/or tagged in accordance with the 
owner-user's procedures, and drain 
valves or cocks between the two closed 
stop valves be opened. After draining 
the boiler, the blowoff valves shall be 
closed, locked out, and/or tagged out 
in accordance with the owner-user's 



2.2.7 



procedures. Alternatively, lines may be 
blanked or sections of pipe removed. 
Blowoff lines, where practicable, shall 
be disconnected between pressure 
parts and valves. All drains and vent 
lines shall be open. 

The Inspector shall review all personnel 
safety requirements as outlined in 1.4 
prior to entry. 

Note: If a boiler has not been properly 
prepared for an internal inspection, 
the inspector shall decline to make the 
inspection. 



EVIDENCE OF LEAKAGE 



a) It is not normally necessary to remove in- 
sulating material, masonry, or fixed parts 
of a boiler for inspection, unless defects 
or deterioration arc suspected or are com- 
monly found in the particular type of boiler 
being inspected. Where there is evidence 
of leakage showing on the covering, the In- 
spector shall have the covering removed in 
order that a thorough inspection of the area 
may be made. Such inspection may require 
removal of insulating material, masonry, or 
fixed parts of the boiler. 

b) For additional information regarding a leak 
in a boiler or determining the extent of a 
possible defect, a leak test may be per- A07 
formed per 4.3.3. 



2.2.8 BOILER CORROSION 

CONSIDERATIONS 

a) Corrosion causes deterioration of the metal 
surfaces. It can affect large areas or it can 
be localized in the form of pitting. Isolated, 
shallow pitting is not considered serious if 
not active. 



z i 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



b) The most common causes of corrosion in 
boilers are the presence of free oxygen and 
dissolved salts in the feedwater. Where 
active corrosion is found, the Inspector 
should advise the owner or user to obtain 
competent advice regarding proper feed- 
water treatment. 

c) For the purpose of estimating the effect of 
severe corrosion over large areas on the safe 
working pressure, the thickness of the re- 
maining sound metal should be determined 
by ultrasonic examination or by drilling. 

d) Grooving is a form of metal deterioration 
caused by localized corrosion and may be 
accelerated by stress concentration. This is 
especially significant adjacent to riveted 
joints. 

e) All flanged surfaces should be inspected, 
particularly the flanges of unstayed heads. 
Grooving in the knuckles of such heads is 
common since there is slight movement in 
heads of this design which causes a stress 
concentration. 

f) Some types of boilers have ogee or re- 
versed-flanged construction which is prone 
to grooving and may not be readily acces- 
sible for examination. The Inspector should 
insert a mirror through an inspection open- 
ing to examine as much area as possible. 
Other means of examination such as the 
ultrasonic method may be employed. 

g) Grooving is usually progressive and when 
it is detected, its effect should be carefully 
evaluated and corrective action taken. 

h) The fireside surfaces of tubes in horizontal 
firetube boilers usually deteriorate more 
rapidly at the ends nearest the fire. The 
Inspector should examine the tube ends to 
determine if there has been serious reduc- 
tion in thickness. The tube surfaces in some 
vertical tube boilers are more susceptible 
to deterioration at the upper ends when 
exposed to the heat of combustion. These 



k) 



tube ends should be closely examined to 
determine if there has been a serious re- 
duction in thickness. The upper tube sheet 
in a vertical "dry top" boiler should be 
inspected for evidence of overheating. 

Pitting and corrosion on the waterside sur- 
faces of the tubes should be examined. In 
vertical firetube boilers, excessive corrosion 
and pitting is often noted at and above the 
water level. 

The surfaces of tubes should be carefully 
examined to detect corrosion, erosion, 
bulges, cracks, or evidence of defective 
welds. Tubes may become thinned by 
high velocity impingement of fuel and ash 
particles or by the improper installation 
or use of soot blowers. A leak from a tube 
frequently causes serious corrosion or ero- 
sion on adjacent tubes. 

In restricted fireside spaces, such as where 
short tubes or nipples are used to join 
drums or headers, there is a tendency for 
fuel and ash to lodge at junction points. 
Such deposits are likely to cause corrosion 
if moisture is present, and the area should 
be thoroughly cleaned and examined. 



2.2.9 



WATERSIDE DEPOSITS 



a) All accessible surfaces of the exposed metal 
on the waterside of the boiler should be 
inspected for deposits caused by water 
treatment, scale, oil, or other substances. 
Oil or scale in the tubes of watertube boil- 
ers is particularly detrimental since this 
can cause an insulating effect resulting in 
overheating, weakening, possible metal 
fatigue, bulging, or rupture. 

b) Excessive scale or other deposits should 
be removed by chemical or mechanical 
means. 



22 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



2.2.10 INSPECTION OF BOILER 
PIPING, PARTS, AND 

APPURTENANCES 



2.2.10.1 BOILER PIPING 

Piping should be inspected in accordance 

with 2.4. 



2.2.10.2 STAYS AND STAYBOLTS 



externally. Whenever possible, observation 
should be made from both sides, internally 
and externally, to determine whether con- 
nections are properly made to the boiler. 

b) All openings leading to external attach- 
ments, such as water column connections, 
low water fuel cut-off devices, openings in 
dry pipes, and openings to safety valves, 
should be examined to ensure they are free 
from obstruction. 



a) All stays, whether diagonal or through, 
should be inspected to determine whether 
or not they are in even tension. Staybolt 
ends and the stayed plates should be exam- 
ined to determine whether cracks exist. In 
addition, stayed plates should be inspected 
for bulging in the general area of the stay. 
Each staybolt end should be checked for 
excessive cold working (heading) and seal 
welds as evidence of a possible leakage 
problem. Stays or staybolts that are not 
in tension or adjustment should be re- 
paired. Broken stays or staybolts shall be 
replaced. 

b) The Inspector should test firebox staybolts 
by tapping one end of each bolt with a 
hammer and, where practicable, a hammer 
or other heavy tool should be held on the 
opposite end to make the test more effec- 
tive. An unbroken bolt should give a ring- 
ing sound while a broken bolt will give a 
hollow or non-responsive sound. Staybolts 
with telltale holes should be examined for 
evidence of leakage, which will indicate a 
broken or cracked bolt. Broken staybolts 
shall be replaced. 



2.2.10.3 FLANGED OR OTHER 
CONNECTIONS 

a) The manhole and reinforcing plates, as well 
as nozzles or other connections flanged or 
bolted to the boiler, should be examined 
for evidence of defects both internally and 



2.2.10.4 MISCELLANEOUS 

a) The piping to the water column should be 
carefully inspected to ensure that water 
cannot accumulate in the steam connec- 
tion. The position of the water column 
should be checked to determine that the 
column is placed in accordance with the 
original code of construction or jurisdic- 
tional requirements. 

b) The gas side baffling should be inspected. 
Absence of proper baffling or defective 
baffling can cause high temperatures and 
overheat portions of the boiler. The location 
and condition of combustion arches should 
be checked for evidence of flame impinge- 
ment, which could result in overheating. 

c) Any localization of heat caused by improper 
or defective installation or improper opera- 
tion of firing equipment shall be corrected 
before the boiler is returned to service. 

d) The refractory supports and settings should 
be carefully examined, especially at points 
where the boiler structure comes near the 
setting walls or floor, to ensure that deposits 
of ash or soot will not bind the boiler and 
produce excessive strains on the structure 
due to the restriction of movement of the 
parts under operating conditions. 

e) When tubes have been re-rolled or re- 
placed, they should be inspected for proper 
workmanship. Where tubes are readily ac- 



23 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



cessible, they may have been over rolled. 
Conversely, when it is difficult to reach 
the tube ends, they may have been under 
rolled. 

f) Drums and headers should be inspected 
internally and externally for signs of leak- 
age, corrosion, overheating, and erosion. 
Inspect blovvdown piping and connections 
for expansion and flexibility. Check header 
seals for gasket leakage. 

g) Soot blower mechanical gears, chains, pul- 
leys, etc., should be checked for broken 
or worn parts. Inspect supply piping to the 
soot blowers for faulty supports, leakage, 
and expansion and contraction provisions. 
Check design for proper installation to al- 
low for complete drainage of condensate, 
which may cause erosion. 

h) Valves should be inspected on boiler feed- 
water, blowdown, drain, and steam systems 
for gland leakage, operability, tightness, 
handle or stem damage, body defects, and 
general corrosion. 



2.2.10.5 GAGES 

a) Ensure that the water level indicated is cor- 
rect by having the gage tested as follows: 

1 ) Close the lower gage glass valve, then 
open the drain cock and blow the glass 
clear. 

2) Close the drain cock and open the 
lower gage glass valve. Water should 
return to the gage glass immediately. 

3) Close the upper gage glass valve, then 
open the drain cock and allow the wa- 
ter to flow until it runs clean. 

4) Close the drain cock and open the 
upper gage glass valve. Water should 
return to the gage glass immediately. 



5) If the water return is sluggish, the test 
should be discontinued. A sluggish 
response could indicate an obstruction 
in the pipe connections to the boiler. 
Any leakage at these fittings should be 
promptly corrected to avoid damage to 
the fittings or a false waterline indica- 
tion. 

b) Unless there is other information to assess A07 
its accuracy or reliability, all the pressure 
gages shall be removed, tested, and their 
readings compared to the readings of a cali- 
brated standard test gage or a dead weight 
tester. 

c) The location of a steam pressure gage 
should be noted to determine whether it is 
exposed to high temperature from an exter- 
nal source or to internal heat due to lack of 
protection by a proper siphon or trap. The 
Inspector should check that provisions are 
made for blowing out the pipe leading to 
the steam gage. 

d) The Inspector should observe the pressure 
gage reading during tests; for example, the 
reduction in pressure when testing the low 
water fuel cutoff control or safety valve 
on steam boilers. Defective gages shall be 
replaced. 



2.2.10.6 PRESSURE RELIEF DEVICES 

See 2.5 for the inspection of safety devices 
(pressure relief valves) used to prevent overpres- 
sure of boilers. 



2.2.10.7 CONTROLS 

a) Verify operation of low water protection de- 
vices by observing the blowdown of these 
controls or the actual lowering of boiler 
water level under carefully controlled con- 
ditions with the burner operating. This test 
should shut off the heat source to the boiler. 



24 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



The return to normal condition such as the 
restart of the burner, the silencing of an 
alarm, or stopping of a feed pump should 
be noted. A sluggish response could indi- 
cate an obstruction in the connections to 
the boiler. 

b) The operation of a submerged low water 
fuel cutoff mounted directly in a steam 
boiler shell should be tested by lowering the 
boiler water level carefully. This should be 
done only after being assured that the water 
level gage glass is indicating correctly. 

c) On a high-temperature water boiler, it is 
often not possible to test the control by 
cutoff indication, but where the control is 
of the float type, externally mounted, the 
float chamber should be drained to check 
for the accumulation of sediment. 

d) In the event controls are inoperative or the 
correct water level is not indicated, the 
boiler shall betaken out of service until the 
unsafe condition has been corrected. 

e) All automatic low water fuel cutoff and wa- 
ter feeding devices should be examined by 
the Inspector to ensure that they are prop- 
erly installed. The Inspector should have 
the float chamber types of control devices 
disassembled and the float linkage and 
connections examined for wear. The float 
chamber should be examined to ensure that 
it is free of sludge or other accumulation. 
Any necessary corrective action shall be 
taken before the device is placed back into 
service. The Inspector should check that the 
operating instructions for the devices are 
readily available. 

f) Check that the following controls/devices 
arc provided: 

1) Each automatically fired steam boiler 
is protected from over pressure by not 
less than two pressure operated con- 
trols, one of which may be an operating 
control. 



2) Each automatically fired hot-water boil- 
er is protected from over-temperature 
by not less than two temperature oper- 
ated controls, one of which may be an 
operating control. 

3) Each hot-water boiler is fitted with a 
thermometer that will, at all times, in- 
dicate the water temperature at or near 
the boiler outlet. 



2.2.11 RECORDS REVIEW 

a) A review of the boiler log, records of main- 
tenance, and feedwater treatment should be 
made by the Inspector to ensure that regular 
and adequate tests have been made on the 
boiler and controls. 

b) The owner or user should be consulted re- 
garding repairs or alterations, if any, which 
have been made since the last inspection. 
Such repairs or alterations should be re- 
viewed for compliance with the jurisdic- 
tional requirements, if applicable. 



2.2.12 DESCRIPTION AND CONCERNS A07 

OF SPECIFIC TYPES OF BOILERS 

The following details are unique to specific 
type boilers and should be considered when 
performing inspections along with the general 
requirements as previously outlined. 



2.2.12.1 WATERTUBE BOILERS 

a) Typically constructed of drums, headers, 
and tubes, watertube boilers are used to 
produce steam or hot water commonly 
in large quantities. They range in size 
and pressure from small package units to 
extremely large field erected boilers with 
pressures in excess of 3000 psig (21 MPa). 
These boilers may be fired by many types 
of fuels such as wood, coal, gas, oil, trash, 



Z5 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



and black liquor. Their size and type of 
construction poses mechanical and thermal 
cyclic stresses. 

b) There are many locations both internal and 
external where moisture and oxygen com- 
bine causing primary concern for corrosion. 
The fuels burned in watertu.be boilers may 
contain ash, which can form an abrasive 
grit in the flue gas stream. The abrasive ac- 
tion of the ash in high velocity flue gas can 
quickly erode boiler tubes. 

c) Unique parts associated with this type of 
construction such as casing, expansion 
supports, superheater, economizer, soot 
blowers, drums, headers, and tubes should 
be inspected carefully and thoroughly in 
accordance with 2.2. 



2.2.12.2 KRAFT OR SULFATE BLACK 

LIQUOR RECOVERY BOILERS 

a) Kraft or Sulfate Black Liquor Recovery 
boilers are used in the pulp and paper 
industry. Black liquor is a by-product of 
pulp processing. It contains organic and 
inorganic constituents concentrated to at 
least 58% solids for firing in the recovery 
boilers. The organic material that is dis- 
solved in the pulping process combusts, 
and the spent pulping chemicals form a 
molten pool in the furnace. The molten 
material, or "smelt," drains from the furnace 
wall through smelt spouts into a smelt dis- 
solving tank for recovery of the chemicals. 
Ultimately, the by-product of the recovery 
process is steam used for processing and 
power. Gas or oil auxilliary burners are 
used to start the self-sustaining black liquor 
combustion process and may be used to 
produce supplemental steam if sufficient 
liquor is not available. 

b) The recovery combustion process requires a 
reducing atmosphere near the furnace floor 
and an oxidizing atmosphere in the upper 
furnace for completion of combustion. 



Pressure parts within the furnace require 
protection from the reducing atmosphere 
and from sulfidation. The rate of corrosion 
within the furnace is temperature depen- 
dent. Boilers operating up to 900 psi (6.21 
MPa) typically have plain carbon steel 
steam generating tubes with pin studs ap- 
plied to the lower furnace to retain a pro- 
tective layer of refractory or "frozen" smelt. 
Above 900 psi (6.2 1 MPa) the lower furnace 
tubes will typically have a special corrosion 
protection outer layer. The most common 
is a stainless steel clad "composite tube." 
Other protection methods are corrosion re- 
sistant overlay welding, thermal or plasma 
spray coating, and diffusion coating. 

c) The unique hazard of these boilers is the 
potential for an explosion if water should 
be combined with the molten smelt. The 
primary source of water is from pressure 
part failure, permitting water to enter the 
furnace. The owner's inspection program is 
carefully developed and executed at appro- 
priate intervals to avoid pressure part failure 
that could admit water to the furnace. A 
second source of water is the liquor fuel. 

d) Permitting black liquor of 58% or lower 
solids content to enter the furnace can also 
result in an explosion. The black liquor fir- 
ing controls include devices that monitor 
and automatically divert the liquor from the 
furnace if solids content is 58% or lower. 

e) In addition to the general inspection re- 
quirements for all watertube-type boilers, 
particular awareness in the following areas 
is necessary: 

1 ) Furnace — the type and scope of wall, 
roof, and water screen lube inspection 
is dependent on materials of construc- 
tion, type of construction, and mode of 
boiler operation. In all cases, furnace 
wall opening tubes need inspection 
for thinning and cracking. The typical 
water-cooled smelt spout can admit 
water to the furnace if the spout fails. 



26 



NATIONAL BOARD INSPECTION CODE 8 PART 2 



INSPECTION 



Common practice is to replace these 
spouts in an interval shorter than that 
in which failure is known to occur. 

2) Water — percentage of solids contained 
in the black liquor before entering the 
furnace shall be closely monitored. 
Verify that the black liquor firing system 
will automatically divert the liquor if 
solids drop to or below 58%. 

3) Corrosion/erosion -- the potential 
consequences of corrosion or erosion 
(smelt-water explosion due to pres- 
sure-retaining part failure) requires a 
well planned and executed inspection 
program by the owner. Maintenance of 
boiler water quality is crucial to mini- 
mizing tube failure originating from the 
water side. 

4) Tubes — depending on type of con- 
struction, inspect for damage such as 
loss of corrosion protection, thinning, 
erosion, overheating, warping, elonga- 
tion, bulging, blistering, and misalign- 
ment. If floor tubes may have been 
mechanically damaged or overheated, 
clean the floor and perform the appro- 
priate type of inspection for suspected 
damage. Excursions in water treatment 
may result in scale and sludge on in- 
ternal surfaces, creating conditions of 
poor heat transfer and ultimately caus- 
ing tube cracks or rupture. 

5) Welds — leaks frequently originate at 
welds. The owner and repair agency 
should carefully plan and inspect all 
repair welds and seal welds that could 
admit water to the furnace. Tube butt 
welds that could admit water to the 
furnace should be examined by a 
volumetric NDE method acceptable to 
the inspector. Tube leaks at attachment 
welds may originate from the internal 
stress-assisted corrosion (SAC). Minor 
upsets in boiler water quality and im- 
proper chemical cleaning may initiate 
SAC. 



6) Emergency Response to Water Entering 
Furnace operators of Kraft recovery 
boilers should have a plan to imme- 
diately terminate all fuel firing and 
drain water from the boiler if a tube is 
known or suspected to be leaking into 
the furnace. This system may be called 
"Emergency Shutdown Procedure" or 
"ESP." The inspector should confirm 
the ESP is tested and maintained such 
that it will function as intended and 
that operators will activate the system 
when a leak into the furnace occurs or 
is suspected. 

7) Overheating — tube rupture due to 
overheating from low water level may 
admit water to the; furnace. The inspec- 
tor should verify a redundant low-wa- 
ter protection system is provided and 
maintained. 

f) Recommended procedures for inspection of 
black liquor recovery boilers are identified 
below: 

1) American Forest and Paper Association 
"Recovery Boiler Reference Manual 
for Owners and Operators of Kraft 
Recovery Boilers," sponsored by the 
Operations/Maintenance Subcommit- 
tee of the Recovery Boiler Committee, 
Volumes I, II, and III (current published 
editions); 

2) The Black Liquor Recovery Boiler 
Advisory Committee, Recommended 
Practices: 

a. Emergency Shutdown Procedure 
(ESP) and Procedure tor Testing 
ESP 

b. Safe Firing of Black liquor Recovery 
Boilers 

c. System for Black Liquor Boilers 

d. Safe Firing of Black Liquor in Black 
Liquor Recovery Boilers 



27 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



e. Safe Firing of Auxiliary Fuel in Black 
Liquor Recovery Boilers 

f. Thermal Oxidation of Waste Streams 
in Black Liquor Recovery Boilers 

g. Instrumentation Checklist and Clas- 
sification Guide for Instruments 
and Control Systems used in the 
Operation of Black Liquor Recovery 
Boilers 

h. Recommended Guidelines for Per- 
sonnel Safety 

3) Technical Association of the Pulp and 
Paper Industry (TAPPI), Technical Infor- 
mation Papers: 

a. 0402-13, Guidelines for Specifi- 
cation and inspection of Electric 
Resistance Welded (ERW) and 
Seamless Boiler Tube for Critical 
and Non-Critical Service 

b. 0402-1 5, Installation and Repair of 
Pin Studs in Black Liquor Recovery 
Boilers 

c. 0402-18, Ultrasonic Testing (UT) 
for Tube Thickness in Black Liquor 
Recovery Boilers 

1 . Part I: Guidelines for Accurate 
lube Thickness Testing 

2. Part II: Default Layouts for 
Tube Thickness Surveys in 
Various Boiler Zones 

d. 0402-21, Ultrasonic Technician 
Performance Test for Boiler Tube 
Inspection 

e. 0402-30, Inspection for Cracking 
of Composite Tubes in Black Liquor 
Recovery Boilers 



f. 0402-31, Guidelines for Evaluat- 
ing the Quality of Boiler Tube Butt 
Welds with Ultrasonic Testing 

g. 0402-33, Guideline for Obtaining 
High Quality Radiographic Testing 
(RT) of Butt Welds in Boiler Tubes 



2.2.12.3 THERMAL FLUID HEATERS 
a) Design and Operating Features 

1 ) Many thermal fluid heaters are pressure 
vessels in which a synthetic or organic 
fluid is heated or vaporized. Some A07 
thermal fluid heaters operate at atmo- 
spheric pressure. The fluids are typically 
flammable, are heated above the liquid 
flash point, and may be heated above 

the liquid boiling point. The heaters are 
commonly direct-fired by combustion 
of a fuel or by electric resistance ele- 
ments. Heater design may be similar to 
an electric resistance heated boiler, to 
a firetube boiler or, more commonly, 
to a vvatertube boiler. Depending on 
process heating requirements, the 
fluid may be vaporized with a natural 
circulation, but more often, the fluid 
is heated and circulated by pumping 
the liquid. Use of thermal fluid heating 
permits heating at a high temperature 
with a low system pressure (600°F to 
700°F [316°C to 371 °C] at pressures 
just above atmospheric). To heat water 
to those temperatures, would require 
pressures of at least 1530 psig (10.55 
MPa). 

2) Nearly all thermal heating fluids are 
flammable. Leaks within a fired heater 
can result in destruction of the heater. 
Leaks in external piping can result in 
fire and may result in an explosion. Wa- 
ter accumulation in a thermal heating 
system may cause upsets and possible 
flu id release from the system if the water 
contacts heated fluid (remember, flash- 



2B 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



ing water expands approximately 1 600 
times). It is essential for safe system 
operation to have installed and to main- 
tain appropriate fluid level, temperature 
and flow controls for liquid systems, 
and level, temperature and pressure 
A07 controls for vapor systems. Expansion 

tanks used in thermal heater systems, 
including vented systems, should be 
designed and constructed to a recog- 
nized standard such as ASME Section 
VIII, Div. 1 , to withstand pressure surges 
that may occur during process upsets. 
This is due to the rapid expansion of 
water exceeding the venting capabil- 
ity. 

3) Because heat transfer fluids contract 
and become more viscous when 
cooled, proper controls and expansion 
tank venting are required to prevent 
low fluid level and collapse of the 
tank. Some commonly used fluids will 
solidify as high as 54°F (12°C). Others 
do not become solid until -40°F (-40 3 C) 
or even lower. The fluids that become 
viscous will also become difficult to 
pump when cooled. Increased viscos- 
ity could cause low flow rates through 
the heater. The heater manufacturer 
recommendations and the fluid man- 
ufacturer's Material Safety Data Sheets 
(MSDS) should be reviewed for heat 
tracing requirements. 

b) Industrial Applications 

Thermal fluid heaters, often called boilers, 
are used in a variety of industrial applica- 
A07 tions such as solid wood products manufac- 
turing resins, turpentines, and various types 
of chemicals, drugs, plastics, corrugating 
plants, and wherever high temperatures are 
required. They are also frequently found 
in asphalt plants for heating of oils, tars, 
asphalt pitches, and other viscous materi- 
als. Many chemical plants use this type of 
heater in jacketed reactors or other types 
of heat exchangers. 



c) Inspection 

1) Inspection of thermal fluid heaters 
typically is done in either the operating 
mode or the shutdown mode. Internal 
inspections, however, are rarely pos- 
sible due to the characteristics of the 
fluids and the need to drain and store 
the fluid. Reliable and safe operation 
of a heater requires frequent analysis of 
the fluid to determine that its condition 
is satisfactory for continued operation. 
If the fluid begins to breakdown, carbon 
will form and collect on heat transfer 
surfaces within the heater. Overheat- 
ing and pressure boundary failure may 
result. Review of fluid test results and 
control and safety device maintenance 
records are essential in determining 
satisfactory conditions for continued 
safe heater operation. 

2) Due to the unique design and material 
considerations of thermal fluid heat- 
ers and vaporizers, common areas of 
inspection are: 

a. Design -- specific requirements 
outlined in construction codes must 
be met. Some Jurisdictions may re- 
quire ASME Section I or Section VI 1 1 
construction. Code requirements 
for the particular Jurisdiction should 
be reviewed for specific design 
criteria. 

b. Materials — for some thermal flu- 
ids, the use of aluminum or zinc 
anywhere in the system is not advis- 
able;. Aluminum acts as a catalyst 
that will hasten decomposition of 
the fluid. In addition, some fluids 
when hot will cause aluminum 
to corrode rapidly or will dissolve 
zinc. The zinc will then form a 
precipitate that can cause localized 
corrosion or plug instrumentation, 
valves, or even piping in extreme 
cases. These fluids should not be 



29 



NATIDNAL BOARD INSPECTION CODE • PART 2 -- INSPECTION 



A07 



A08 



e. 



used in systems containing alumi- 
num or galvanized pipe. The fluid 
specifications will list such restric- 
tions. 

Note: Some manufacturers of these 
fluids recommend not using alumi- 
num paint on valves or fittings in 
the heat transfer system. 

Corrosion — when used in ap- 
plications and installations recom- 
mended by fluid manufacturer, 
heat transfer fluids are typically 
noncorrosive. However, some flu- 
ids, if used at temperatures above 
1 50°F (65 C C) in systems containing 
aluminum or zinc can cause rapid 
corrosion. 

Leakage — any sign of leakage 
could signify problems since the 
fluid or its vapors can be hazard- 
ous as well as flammable. Areas 
for potential leaks include cracks 
at weld attachment points and tube 
thinning in areas where tubes are 
near soot blowers. The thermal fluid 
manufacturer specifications will list 
the potential hazards. 

Solidification of the Fluid — deter- 
mine that no conditions exist that- 
would allow solidification of the 
thermal fluid. When heat tracing or 
insulation on piping is recommend- 
ed by the heater manufacturer, the 
heat tracing and insulation should 
be checked for proper operation 
and installation. 

Pressure Relief Devices — Pressure 
relief valves shall be a closed bon- 
net design with no manual lift lever. 
The pressure relief discharge should 
be connected to a closed, vented 
storage tank or blowdovvn tank 
with solid piping. When outdoor 



discharge is used, the following 
should be considered for discharge 
piping at the point of discharge: 



1. Both thermal and chemical 
reactions (personnel hazard) 

2. Combustible materials (fire 
hazard) 

'.). Surface drains (pollution and 
fire hazard) 

4. Loop seal or rain cap on the 
discharge (keep both air and 
water out of the system) 

5. Drip leg near device (prevent 
liquid collection) 

b. Heal tracing for systems using 
high freeze point fluids (pre- 
vent blockage) 



2.2.12.4 WASTE HEAT BOILERS 

a) Waste heat boilers are usually of firetube or 
watertube type and obtain their heat from 
an external source or process in which a 
portion of the BTUs have been utilized. 
Generation of electrical energy is usually 
the primary application of waste heat boil- 
ers. The biggest disadvantage of this type 
of boiler is that it is not fired on the basis 
of load demand. Since the boiler does not 
have effective control over the amount of 
heat entering the boiler, there may be wide 
variations or fluctuations of metal tempera- 
tures. Waste process gasses are usually in 
a temperature range of 40G"T (205°C) to 
800°F (427°C), where combustion gasses 
of conventional-fired boilers are at about 
2000°F (1 093°Q. Special design consider- 
ations are made to compensate for lower 
combustion gas temperatures such as the 
use of finned high-efficiency heat absorbing 
tubes, and by slowing the velocity of gasses 
through the boiler. 



30 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



b) Due to the unique design and material 
considerations of waste heat boilers, the fol- 
lowing are common areas of inspection: 

1) Corrosion — chemicals in waste heat 
gasses may create corrosive conditions 
and react adversely when combined 
with normal gasses of combustion. 
Water or steam leakage can create 
localized corrosion. Extreme thermal 
cycling can cause cracks and leakage 
at joints. 

2) Erosion — typically waste heat flow is 
very low and erosion is not a problem. 
However, when waste heat is supplied 
from an internal combustion engine, 
exhaust gasses can be high enough to 
cause erosion. 

3) Vibration — in some process applica- 
tions and all engine waste heat appli- 
cations, the boiler may be subjected to 
high vibration stresses. 

4) Acid Attack — in sulfuric acid processes 
refractory supports and steel casings are 
subject to acid attack. Piping, filters, 
heat exchangers, valves, fittings, and 
appurtenances are subject to corrosive 
attacks because these parts are not 
normally made of corrosion resistant 
materials. 

5) Dry Operation — in certain applica- 
tions waste heat boilers are operated 
without water. Care must be taken not 
to expose carbon steel material to tem- 
peratures in excess of 800°F (427 C C) for 
prolonged periods. Carbides in the steel 
may precipitate to graphite at elevated 
temperatures. 



2.2.12.5 CAST-IRON BOILERS 

a) Cast-iron boilers are used in a variety of 

applications to produce low or high pres- 

A07 sure steam and hot water heat. Cast-iron 

boilers should only be used in applica- 



tions that allow for nearly 100% return of 
condensate or water, and are not typically 
used in process-type service. These boilers 
are designed to operate with minimum 
scale, mud, or sludge, which could occur 
if makeup water is added to this system. 

b) Due to the unique design and material 
considerations of cast-iron boilers, the fol- 
lowing are common areas of inspection: 

1 ) Scale and Sludge — since combustion 
occurs at or near the bottom, accumu- 
lation of scale or sludge close to the 
intense heat can cause overheating and 
lead to cracking. 

2) Feedwater — makeup feedwater should 
not come in contact with hot surfaces. 
Supply should be connected to a return 
pipe for tempering. 

3) Section Alignment — misalignment of 
sections can cause leakage. Leakage or 
corrosion between sections will not al- 
low normal expansion and contraction 
that may cause cracking. 

4) Tie Rods or Draw Rods — used to as- 
semble the boiler and pull the sections 
together. These rods must not carry any 
stress and need to be loose, allowing 
for section growth during heat up. 
Expansion washers may be used and 
nuts should be just snugged allowing 
for expansion. 

5) Push Nipple or Seal Area — corrosion 
or leakage is likely at the push nipple 
opening, usually caused by the push 
nipple being pushed into the seat 
crooked, warping due to overheating, 
tie rods too tight, and push nipple cor- 
rosion/erosion. 

6) Corrosion — firesides of sections 
can corrode due to ambient moisture 
coupled with acidic flue gas deposits. 



3 i 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



7) Soot — inadequate oxygen supply or 
improperly adjusted burner can allow 
for sool buildup in fireside passages. A 
reduction in efficiency and hot spots 
may occur. Soot, when mixed with wa- 
ter, can form acidic solutions harmful 
to the metal. 



and may be used in conjunction with a 
hot-water storage vessel. 

b) Due to the unique design and material 
considerations of fired coil water heaters, 
the following are common areas of inspec- 
tion: 



2.2.12.6 ELECTRIC BOILERS 

a) Electric boilers are heated by an electrical 
energy source, either by use of electric re- 
sistant coils or induction coils. These boilers 
may be used in either high or low pressure 
steam or hot water applications. 

b) Due to the unique design and material con- 
siderations of electric boilers, the following 
are common areas of inspection: 

1 ) Weight Stress of the Elements — some 
electrodes and elements can be quite 
heavy, especially if covered with scale 
deposits. These elements will scale 
sooner and at a faster rate than internal 
surfaces. Excessive weight puts severe 
stress on the attachment fittings and 
welds at support points. 

2) Thermal Shock — healers are constantly 
cycling on and off creating temperature 

AQ7 gradients, but are less susceptible to 

thermal shock than a fired boiler. 

3) Leakage — any leakage noted at the 
opening where electrodes or elements 
are inserted is extremely dangerous due 
to the possible exposure of electrical 
wires, contacts, and breakers. 



2.2.12.7 FIRED COIL WATER HEATERS 

a) Fired coil water heaters are used for rapid 
heating of potable water or hot water ser- 
vice. This design utilizes a coil through 
which the water being heated is passed. 
This type of heater has very little volume 



1) Erosion — size and velocity of water 
flow through the coil combines to 
create wear and thinning of the coils. 
If a temperature differential is created 
within the coil, bubbles or steam may 
cause grooving or cavitation. 

2) Corrosion — this type of system uses 
100% makeup water that contains 
free oxygen creating opportunities for 
extensive corrosion. 

3) Vibration — operation of the burner 
creates a certain amount of vibration. 
Creation of steam, hot spots, or lack of 
flow may create a water hammer caus- 
ing extensive vibration and mechanical 
stresses. 

4) Scale — due to the large volume of 
makeup, significant amounts of scale 
forming particles will adhere to the hot 
surfaces. 



2.2.12.8 FIRED STORAGE WATER 
HEATERS 

a) Fired storage water healers are vertical 
pressure vessels containing water to which 
heat is applied. Typically gas burners are 
located directly beneath ihe storage vessel. 
These heaters should be insulated and fitted 
with an outer jacket and maybe lined with 
porcelain, glass, galvanized metal, cement, 
or epoxy. 

b) Due to the unique design and material 
considerations of fired storage water heat- 
ers, the following are common areas of 
inspection: 



32 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



1 ) Corrosion — moisture may be trapped 
between the insulation and outer 
jacket, which may cause corrosion of 
the pressure boundary. 

2) Mud and Sludge — there is 100% 
makeup of water allowing for accumu- 
lation of mud and sludge in the bottom 
portions of the vessel. Any buildup can 
cause overheating and failure of the 
metal in this area. 

3) Scale — loose scale may accumulate in 
areas adjacent to the burner and lower 
portions of the vessel, interfering with 
heat transfer process and causing local- 
ized overheating. Scale and sludge can 
also shield temperature control probes 
giving false readings and allowing the 
water to overheat. 

4) Thermal Cycling — heated water is con- 
tinually replaced with cold water caus- 
ing thermal stress within the vessel. 

5) Lining — loss of lining or coating will 
allow for rapid deterioration of the pres- 
sure boundary. 

6) Pressure — if water supply pressure 
exceeds 75% of set pressure of safety 
relief valve, a pressure reducing valve 
may be required. 

7) Expansion — if the water heater can 
be isolated by devices such as a check 
valve, it is recommended that an expan- 
sion tank be provided. 



2.2.12.9 FIRETUBE BOILERS 

a) The distinguishing characteristic of a fire- 
tube boiler is that the products of combus- 
tion pass within tubes that are surrounded 
by the water that is being heated. Combus- 
tion of fuel takes place within the furnace 
area with the resultant products of combus- 
tion traveling through one or more groups 



of tubes before exiting the boiler. Firetube 
boilers are classified by the arrangement of 
the furnace and tubes such as Horizontal 
Return Tubular (HRT) boiler, Firetube Fire 
Box (FTFB) boiler, or Vertical Tubular (VT) 
boiler. The number of passes that the prod- 
ucts of combustion make through the tubes 
is also used in classifying the type of boiler, 
such as a two-pass or three-pass boiler. 

b) Firetube boilers may be used in hot water 
or steam applications. They may be either 
low pressure or high pressure construction, 
but typically are not designed for pressures 
greater than 250 psig. Steam capacities are 
generally less than 30,000 Ib/hr. Firetube 
boilers are found in a wide variety of ap- 
plications ranging from heating to process 
steam to small power generation. 

c) Firetube boilers are subject to thermal 
stresses due to cycling, which may cause 
tube leakage and corrosion of joints. The 
following items are common areas of in- 
spection: 

1) Waterside — scale buildup on and 
around the furnace tube. Scale on or 
around the firetubes in the first pass 
after the furnace (gas temperatures 
>1800°F[980=C1). Scale and corrosion 
buildup on stay rods hiding the actual 
diameter. Corrosion pitting on all pres- 
sure boundaries. 

2) Fireside — Tube to tube sheet joint leak- 
age. Look for rust trails left by weeping 
joints. When in doubt where the leak- 
age is coming from, perform a liquid 
penetrant exam. Take note of refractory 
locations protecting steel that is not 
water cooled. Partial or complete re- 
moval of the refractory may be required 
for inspection purposes. Condensation 
of combustion gas dripping out of the 
fireside gaskets during a cold boiler start 
up is expected. However, if it continues 
after the water temperature in the boiler 
is at least 150°F ((->5°C), then further 



33 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



investigation to determine the source 
of water shall be conducted. 

d) Practical considerations lead to the use 
of basically cylindrical shells. Flat-end 
tubesheet surfaces are supported by various 
methods: diagonal stays, through-bolts, or 
the tubes themselves. Tubes may be rolled, 
welded, or rolled and seal-welded into the 
tubesheets. For steam applications, the wa- 
ter level is maintained several inches above 
the uppermost row of tubes, which allows 
for a steam space in the upper portion of 
the boiler shell. There are several different 
types of firetube boilers: 

1 ) Firetube Scotch Marine (FTSM) 

a. A Firetube Scotch Marine boiler 
consists of a horizontal cylindrical 
shell with an internal furnace. Fuel 
is burned in the furnace with the 
products of combustion making 
two, three, or four passes through 
the boiler tubes. The rear door may 
be either a dry refractory lined de- 
sign (dry back), or a water-cooled 
(wet back) design. Two designs of 
the furnace are commonly used: 
one, the corrugated type, is known 
as a Morrison furnace; the other is 
the plain furnace. 

b. The FTSM boiler design is one of 
the oldest firetube boiler designs 
with internal furnaces. Extensive 
use in early marine service added 
"marine" to the name of this type of 
boiler. Currently both the wet back 
design and the dry back design can 
be found in stationary applications. 
Firetube Scotch marine boilers are 
used for both high pressure and low 
pressure steam applications and are 
also used for hot water service. 

2) Horizontal Return Tubular (HRT) 

A08 a. Horizontal Return Tubular boilers 

consists of a cylindrical shell with 



flat tube sheets on the ends. The A08 
tubes occupy the lower two thirds 
of the shell with a steam space 
above the tubes. The lower portion 
of the shell is enclosed by refactory 
brick work forming the furnace of 
the boiler which is normally quite 
large to accomodate sold fuel firing. 
The shell is supported by the brick 
work or by support beams that are 
connected by buckstays to suspen- 
sion lugs mounted on the shell. This 
type of boiler is highly susceptible 
to overheating of the lower portion 
of the shell due to scale accumula- 
tion that prevents heat transfer from 
the shell to the water. Another area 
of concern is the bottom blowdown 
line which passes through the rear 
of the furnace. It must be protected 
with a refractory baffle to prevent 
direct contact with the products 
of combustion. Another potential 
problem is deterioration of the 
furnace brickwork allowing the 
products of combustion to escape 
and thus reducing efficiency. 

b. HRT boilers were originally used for 
both high pressure and low pres- 
sure steam applications. HRT boil- A08 
ers were quite common in the early 
to mid 1900s. Theses boilers are 
frequently of riveted construction. 
The design is quite inefficient due 
to the one pass design and the large 
amount brickwork that is heated by 
the products of combustion. Units 
that are still in service are typically 
found in old industrial facilities and 
are generally only used for steam 
heating applications. 

3) Firetube Fire Box (FTFB) 

a. FireTube Fire Box boilers were 
popular in the mid 1 900s, although 
many can still be found in service. 



34 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



An FTFB boiler consists of an ex- 2. J 
ternal furnace that is enclosed by 
water legs on three or four sides. 
The water legs extend upward to 2.3.1 
the crownsheet to form the lower 
part of the boiler shell while the 
upper part of the shell is formed by 
the extension of the water leg outer 
shell. Flat heads are used on both 
ends of the boiler shell. The boilers 
A07 may be two-, three-, or four-pass 

designs. 

b. Since the water legs of FTFB boilers 2.3.2 
are the lowest point of the water 
side, loose scale and sludge tends a) 
to accumulate. Besides interfering 
with water flow, the accumulated 
sediment may accelerate corrosion 
of water leg stay bolts or the water 
legs themselves. The hand holes in 
the water legs should be open dur- 
ing an internal inspection. 

4) Locomotive 
Locomotive boilers are similar in design 
to the boilers on old steam locomotives. 
This design saw limited stationary ap- 
plications and few remain in service 
today. Most are of riveted construction. 
See Supplement 1 for detailed draw- 
ings. 

5) Vertical Firelube 

As the name implies, vertical firetube 
boilers are arranged with the shell and b) 
tubes in the vertical orientation. These 
boilers are generally small (<1 0,000 lb/ 
hr |< 4, 535.92 kg/hr] capacity) and are 
used where the rapid development of 
steam is necessary for operation. Verti- 
cal firetube boilers are found in many 
high- and low-pressure applications. 
A07 The burner may be located on top or 

bottom of the boiler. Due to their small 
size and frequent application where 
considerable makeup water is used, 
scale development is an important 
concern. 



PRESSURE VESSELS 



SCOPE 



This section provides guidelines for in service 
inspection of pressure vessels used to contain 
pressure either internal or external. This pres- 
sure may be obtained from an external source 
or by the application of heat from a direct or 
indirect source or a combination thereof. 



SERVICE CONDITIONS 



A07 



Pressure vessels are designed for a variety 
of service conditions. The media that a pres- 
sure vessel contains and the temperature 
and pressure at which it operates should 
be considered in establishing inspection 
criteria. Usage, materials, and installa- 
tion conditions should be considered in 
determining damage mechanisms that 
will affect the mechanical integrity of a 
pressure vessel as described in Section 3 
of this Part. The general requirements for 
safety, pre-inspection, and post-inspection 
activities are specified in Section 1 of this 
Part and should be followed in conjunction 
with the specific requirements outlined in 
this section when performing inspections of 
pressure vessels. There may be occasions 
where more detailed procedures will be 
required. 

The type of inspection given to pressure 
vessels should take into consideration the 
condition of the vessel and the environ- 
ment in which it operates. This inspection 
may be either external or internal and use 
a variety of nondestructive examination 
methods as described in Section 4 of this 
Part. The inspection method may be per- 
formed when the vessel is operating on- 
stream or depressurized, but shall provide 
the necessary information to determine 
that the essential sections of the vessel are 
in satisfactory condition to operate for the 
expected time interval. On-stream inspec- 
tion, including while under pressure, may 



35 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



be used to satisfy inspection requirements 
provided the accuracy of the method can 
be demonstrated. 

New pressure vessels are placed in service 
to operate under their design conditions for 
a period of time determined by the service 
conditions and the corrosion rate. If the 
pressure vessel is to remain in operation, 
the allowable conditions of service and the 
length of time before the next inspection 
shall be based on the conditions of the 
vessel as determined by the inspection. See 
4.4.7 for determining remaining service life 
and inspection intervals. 



2.3.3 



EXTERNAL INSPECTION 



The purpose of an external inspection is to 
provide information regarding the general 
condition of the pressure vessel. The following 
should be reviewed: 

a) Insulation or Other Coverings 

If it is found that external coverings such as 
insulation and corrosion-resistant linings 
are in good condition and there is no rea- 
son to suspect any unsafe condition behind 
them, it is not necessary to remove them for 
inspection of the vessel. However, it may 
be advisable to remove small portions of 
the coverings in order to investigate attach- 
ments, nozzles, and material conditions. 

Note: Precautions should be taken when 
removing insulation while vessel is under 
pressure. 

b) Evidence of Leakage 

Any leakage of gas, vapor, or liquid should 
be investigated. Leakage coming from 
behind insulation coverings, supports or 
settings, or evidence of past leakage should 
be thoroughly investigated by removing 
any covering necessary until the source of 
leakage is established. 



c) Structural Attachments 

The pressure vessel mountings should be 
checked for adequate allowance for expan- 
sion and contraction, such as provided by 
slotted bolt holes or unobstructed saddle 
mountings. Attachments of legs, saddles, 
skirts, or other supports should be exam- 
ined for distortion or cracks at welds. 

d) Vessel Connections 

Manholes, reinforcing plates, nozzles, or 
other connections should be examined for 
cracks, deformation, or other defects. Bolts 
and nuts should be checked for corrosion 
or defects. Weep holes in reinforcing plates 
should remain open to provide visual evi- 
dence of leakage as well as to prevent pres- 
sure buildup between the vessel and the 
reinforcing plate. Accessible flange faces 
should be examined for distortion and to 
determine the condition of gasket-seating 
surfaces. 

e) Miscellaneous Conditions 

1 ) Abrasives — The surfaces of the vessel 
should be checked for erosion. 

2) Dents — Dents in a vessel are deforma- 
tions caused by their coming in contact 
with a blunt object in such a way that 
the thickness of metal is not materially 
impaired. Dents can create stress risers 
that may lead to cracking. 

3) Distortion — If any distortion is sus- 
pected or observed, the overall dimen- 
sions of the vessel shall be checked to 
determine the extent and seriousness 
of the distortion. 

4) Cuts or Gouges — Cuts or gouges can 
cause high stress concentrations and 
decrease the wall thickness. Depending 
upon the extent of the defect, it may be 
necessary to repair. 

5) Surface Inspection — The surfaces of 
shells and heads should be examined 
for possible cracks, blisters, bulges, cor- 



se 



NATIDNAL BOARD INSPECTION CODE • PART Z — INSPECTION 



a. Location and thickness of monitor 
samples and other critical inspec- 
tion locations. 

b. Limiting metal temperature and 
location on the vessel when this is a 
factor in establishing the minimum 
allowable thickness. 

c. Computed required metal thick- 
nesses and maximum allowable 
working pressure for the design 
temperature and pressure-reliev- 
ing device opening pressure, static 
head, and other loadings. 

d. Test pressure, if tested at the time 
of inspection. 

e. Required date of next inspection. 

5) Date of installation and date of any 
significant change in service conditions 
(pressure, temperature, character of 
contents, or rate of corrosion). 

6) Drawings showing sufficient details to 
permit calculation of the service rating 
of all components on pressure vessels 
used in process operations subject to 
corrosive conditions. Detailed data 
with sketches, where necessary, may 
serve this purpose when drawings are 
not available. 



2.3.6 DESCRIPTION AND CONCERNS 

OF SPECIFIC TYPES OF 
PRESSURE VESSELS 

Inspection and examination requirements iden- 
tified below should also include any additional 
requirements mentioned above. 



2.3.6.1 



DE AERATORS 



a) A deaerator is used to remove undesirable 
gases and is exposed to the following ser- 



vice conditions: harmful gases, fluctuation A07 
in temperature and pressure, erosion, and 
vibration. The air and water atmosphere in 
the deaerator has a corrosive effect and may 
contain high concentrations of hydrogen 
ions, which can cause hydrogen crack- 
ing, hydrogen embrittlement, or corrosion 
fatigue. The water entering the deaerator 
sometimes carries acids or oil that can 
cause acidic attacks on the metal. 

b) Inspection shall consist of the following: 

1) Welds — Inspect all longitudinal and 
circumferential welds, including the 
Heat Affected Zone (HAZ), visually 
along their entire length. Examine noz- 
zle and attachment welds for erosion, 
corrosion, or cracking. Inspect with 
special attention all exposed internal 
welds at or below the normal water 
line. 

2) Shell — Inspect exterior surfaces for 
corrosion or leaks. Inspect interior for 
pitting, corrosion, erosion, thinning, 
wastage of metal, cracks, etc. 

3) Spray Nozzles and Trays — Inspect all 
nozzles and spray areas for erosion, 
wear, wastage, and broken parts or 
supports. Check to see that nozzles are 
not plugged and that all lines to nozzles 
are open. Inspect all trays for holes, 
erosion, wastage, broken or defective 
brackets, and broken support attach- 
ments. 

4) Condenser and Vents — Examine all 
vent lines to see that they are open 
to ensure proper exiting of the gases. 
Inspect the condenser unit to verify it 
is operable and not plugged with scale 
or sludge. Check for corrosion, pitting, 
erosion, and broken parts. 

5) Supports — Inspect all support struc- 
tures for mechanical damage, cracks, 
loose bolting, and bent or warped 



39 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



components. Check all welds, espe- 
cially attaching supports to the pressure 
boundary. 



2.3.6.2 COMPRESSED AIR VESSELS 

a) Compressed air vessels include receivers, 
separators, filters, and coolers. Consider- 
ations of concern include temperature vari- 
ances, pressure limitations, vibration, and 
condensation. Drain connections should be 
verified to be free of any foreign material 
that may cause plugging. 

b) Inspection shall consist of the following: 

1) Welds — Inspect all welds for cracking 
or gouging, corrosion and erosion. Par- 
ticular attention should be given to the 
welds that attach brackets supporting 
the compressor. These welds may fail 
due to vibration. 

2) Shells/Heads — Externally, inspect the 
base material for environmental dete- 
rioration and impacts from objects. Hot 
spots and bulges are signs of overheat- 
ing and should be noted and evaluated 
for acceptability. Particular attention 
should be paid to the lower half of the 
vessel for corrosion and leakage. For 
vessels with manways or inspection 
openings, an internal inspection should 
be performed for corrosion, erosion, 
pitting, excessive deposit buildup, and 
leakage around inspection openings. 
UT thickness testing may be used where 
internal inspection access is limited or 
to delermine actual thickness when 
corrosion is suspected. 

3) Fittings and Attachments — Inspect all 
fittings and attachments for alignment, 
support, deterioration, damage, and 
leakage around threaded joints. Any 
internal attachments such as supports, 
brackets, or rings shall be visually ex- 
amined for wear, corrosion, erosion, 
and cracks. 



4) Operation — Check the vessel name- 
plate to determine the allowed working 
pressure and temperature of the vessel. 
Fnsure the set pressure of the safety- 
valve does not exceed that allowed on 
the vessel nameplate and determine 
that the capacity of the safety valve is 
greater than the capacity of the com- 
pressor. Ensure there is a functioning 
manual or automatic condensate 
drain. 

5) Quick-Closure Attachments — Filler- 
type vessels usually have one quick- 
type closure head for making filter 
changes see 2.3.6.5. 



2.3.6.3 EXPANSION TANKS 

a) The purpose of an expansion tank is to 
provide an air cushion to a system that will 
allow for expansion and contraction, thus 
minimizing fluctuations in pressure due to 
temperature variances. These vessels are 
susceptible to corrosion due to the air and 
water interface. 

b) Inspection shall consist of the following; 

1) Design/Operation -■ Verify from the 
nameplate the code of construction, 
temperature, and pressure ratings to en- 
sure jurisdictional and system compat- 
ibility. It is common to find expansion 
tanks water logged due to leakage of air 
out of the tank; therefore, it is important 
to verify the water level either by sight 
glass or sounding the tank. If the vessel 
is fitted with a water sight glass, inspect 
for visual cleanliness, water leakage, 
and gasket tightness. 

2) Surface Conditions — Check all surfac- 
es external and internal, if possible, for 
any leaks, corrosion, erosion, cracks, 
and dents that may lead to failure. 
Thickness checks may be applicable to 
determine any reduction of base mate- 
rial thickness. 



4D 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Supports and Attachments — These 
vessels are usually suspended from the 
ceiling by hangers or straps causing 
concentration of stresses in these areas. 
Specifically inspect for corrosion, wear, 
and cracks in these areas. 



2.3.6.4 LIQUID AMMONIA VESSELS 

Vessels in liquid ammonia service are suscep- 
tible to stress corrosion cracking (SCO (see 
3.3.2 [b]) in areas of high stress. High strength 
and coarse-grained materials seem to be more 
at risk of SCC than are fine-grained or more 
moderate strength materials, although no 
commonly used steels appear to be immune 
to the problem. Postweld heat treatment of 
new or weld-repaired vessels or cold formed 
heads is beneficial in reducing the incidence 
of SCC. The presence of 0.2% minimum water 
in the liquid ammonia also inhibits SCC. Any 
leak should be thoroughly investigated and the 
necessary corrective action initiated. 

a) Inspection of Parts and Appurtenances 

1) Where existing openings permit, per- 
form a visual internal inspection of the 
vessel. Look for any obvious cracks 
(very advanced SCC) and note areas 
that are subject to high stress such as 
welds, welded repairs, head-to-shell 
transitions, sharp interior corners, and 
interior surfaces opposite external at- 
tachments or supports. Alternatively, an 
internal inspection may be conducted 
from the outside utilizing suitable NDE, 
e.g., ultrasonic techniques. 

2) If valves or fittings are in place, check 
to ensure that these are complete and 
functional. Parts made of copper, zinc, 
silver, or alloys of these metals are 
unsuitable for ammonia service and 
should be replaced with parts fabricat- 
ed of steel or other suitable materials. 



3) Fittings should be removed or other- 
wise prolecled from power buffing or 
light sandblasting when preparing the 
interior surface of the vessels for inspec- 
tion. 

4) All interior welds and highly stressed 
areas should be examined by the wet 
fluorescent magnetic particle-testing 
method (VVFMT) using an A/C yoke for 
magnetization. Note that weld cracks 
are often transverse in orientation. It is 
extremely important to ensure that the 
NDE method used will disclose cracks 
in any orientation. 

5) If cracks are discovered, a calculation 
must be made to determine what depth 
of grinding may be carried out for crack 
removal (without encroaching on the 
minimum thickness required by the 
construction standard or equivalent). 

6) Where possible, crack removal by 
grinding is the preferred method of re- 
pair. Since the stresses at the crack tips 
are quite high, even very fine cracking 
should be eliminated. 

7) Where crack depth is such that removal 
requires weld repair, a weld procedure 
should be employed that will minimize 
HAZ hardening and residual stresses. 
Whenever possible, weld repairs re- 
gardless of their size should be post- 
weld heat treated. 

8) Re-inspect by VVFMT to ensure com- 
plete crack removal. 

9) It is not intended to inhibit or limit the 
use of other evaluation methods. It is 
recognized that acoustic emission and 
fracture mechanics are acceptable tech- 
niques for assessing structural integrity 
of vessels. Analysis by fracture mechan- 
ics may be used to assess the structural 
integrity of vessels when complete 



41 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



removal of all ammonia stress cracks is 
not practical. If alternative methods are 
used, the above recommendation that 
all cracks be removed, even fine cracks 
may not apply. 

b) Inspection of Insulated Vessels 

1) Insulated pressure vessels can suffer 
from aggressive external corrosion that 
is often found beneath moist insulation. 
The Inspector should closely examine 
the external insulation scaling surfaces 
for cold spots, bulges, rust stains, or any 
unusual conditions in previous repair 
areas. Bulging or distorted insulation 
on refrigerated vessels may indicate 
the formation of ice patches between 
the vessel shell and insulation due to 
trapped moisture. Careful observation 
is also required where the temperature 
of insulated vessels cycle continu- 
ally through the freezing temperature 
range. 

2) The lower 1/3 to 1/2 and the bottom 
portions of insulated vessels should re- 
ceive special focus, as condensation or 
moisture may gravitate down the vessel 
shell and soak into the insulation keep- 
ing it moist for long periods of time. 
Penetration locations in the insulation 
such as saddle supports, nozzles, or 
fittings should be examined closely for 
potential moisture ingress paths. When 
moisture penetrates the insulation, the 
insulation may actually work in reverse 
holding moisture in the insulation and/ 
or near the vessel shell. 

3) Insulated vessels that are run on an 
intermittent basis, or that have been 
out of service require close scrutiny. 
In general, a visual inspection of the 
external surfaces of insulated vessels 
should be conducted once per year. 

4) The most common and superior method 
to inspect for suspected corrosion un- 



der insulation damage (CUI) is to com- 
pletely or partially remove the insula- 
tion for visual inspection. The method 
most commonly utilized to inspect for 
CUI without insulation removal is by 
x-ray and isotope radiography (film 
or digital) or by real time radiography 
utilizing imaging scopes and surface 
profilers. The real time imaging tools 
will work well if the vessel geometry 
and insulation thickness allows. Other 
less common methods to detect CUI 
include specialized electromagnetic 
methods (pulsed eddy current and 
electromagnetic waves), and long range 
ultrasonic techniques (guided waves). 

5) There are also several methods to detect 
moisture soaked insulation, which is 
often the beginning for potential CUI 
damage. Moisture probe detectors, 
neutron backscatter, and thermogra- 
phy arc tools that can be used for CUI 
moisture screening. 

6) Proper surface treatment (coating) of the 
vessel external shell and maintaining 
weather tight external insulation are the 
keys to prevention of CUI damage. 

c) Gages and Pressure-Relieving Devices 

1 ) The Inspector should note the pressure 
indicated by the gage and compare it 
with other gages on the same system. 
If the pressure gage is not mounted on 
the vessel itself, it should be ascertained 
that the gage is installed on the system 
in such a manner that it correctly indi- 
cates actual pressure in the vessel. 

2) See2.5 for the inspection of safety relief 
devices (pressure relief valves) used to 
prevent the overpressure of liquid am- 
monia vessels. Pressure-relief devices 
in ammonia service shall not be tested 

in place using system pressure. Bench A07 
testing is required. 



42 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



2.3.6.5 INSPECTION OF PRESSURE 
VESSELS WITH QUICK- 
ACTUATING CLOSURES 

a) This section describes guidelines for in- 
spection of pressure vessels equipped 
with quick-actuating closures. Due to the 
many different designs of quick-actuating 
closures, potential failures of components 
that are not specifically covered should be 
considered. The scope of inspection should 
include areas affected by abuse or lack of 
maintenance and a check for inoperable or 
bypassed safety and warning devices. 

b) Temperatures above that for which the 
quick-actuating closure was designed can 
have an adverse effect on the safe operation 
of the device. If parts are found damaged 
and excessive temperatures are suspected 
as the cause, the operating temperatures 
may have exceeded those temperatures 
recommended by the manufacturer. Rapid 
fluctuations in temperatures due to rapid 
start-up and shutdown may lead to cracks 
or yielding caused by excessive warping 
and high thermal stress. A careful observa- 
tion should be made of the condition of 
the complete installation, including main- 
tenance and operation, as a guide in form- 
ing an opinion of the care the equipment 
receives. The history of the vessel should be 
established, including: year built, materials 
of construction, extent of postwcld heat 
treatment, previous inspection results, and 
repairs or alterations performed. Any leak 
should be thoroughly investigated and the 
necessary corrective action initiated. 

1 ) Inspection of Parts and Appurtenances 

a. Seating surfaces of the closure 
device, including but not limited 
to the gaskets, O-rings, or any me- 
chanical appurtenance to ensure 
proper alignment of the closure 
to the seating surface, should be 
inspected. This inspection can be 
made by using powdered chalk or 



any substance that will indicate that 
the closure is properly striking the 
seating surface of the vessel flange. 
If this method is used, a check 
should be made to ensure that: 

1 . Material used will not con- 
taminate the gasket or mate- 
rial with which it comes into 
contact. 

2. The substance used should be 
completely removed after the 
examination. 

b. The closure mechanism of the 
device should be inspected for 
freedom of movement and proper 
contact with the locking elements. 
This inspection should indicate 
that the movable portions of the 
locking mechanism are striking the 
locking element in such a manner 
that full stroke can be obtained. 
Inspection should be made to en- 
sure that the seating surface of the 
locking mechanism is free of metal 
burrs and deep scars, which would 
indicate misalignment or improper 
operation. A check should be made 
for proper alignment of the door 
hinge mechanisms to ensure that 
adjustment screws and locking 
nuts are properly secured. When 
deficiencies are noted, the follow- 
ing corrective actions should be 
initiated: 

1 . If any deterioration of the gas- 
ket, O-ring, etc., is found, the 
gasket, O-ring, etc., should 
be replaced immediately. 
Replacements should be in 
accordance with the vessel 
manufacturer's specifications. 

2. If any cracking or exces- 
sive wear is discovered on 
the closing mechanism, the 
owner or user should contact 



4-3 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



the original manufacturer 
of the device for spare parts 
or repair information. If this 
cannot be accomplished, the 
owner or user should contact 
an organization competent 
in quick-actuating closure 
design and construction prior 
to implementing any repairs. 

■5. Defective safety or warning 
devices should be repaired 
or replaced prior to further 
operation of the vessel. 

4. Deflections, wear, or warping 
of the sealing surfaces may 
cause out-of-roundness and 
misalignment. The manufac- 
turer of the closure should 
be contacted for acceptable 
tolerances for out-of-round- 
ness and deflection. 

5. The operation of the closure 
device through its normal 
operating cycle should be 
observed while under control 
of the operator. This should 
indicate if the operator is fol- 
lowing posted procedures and 
if the operating procedures for 
the vessel arc; adequate. 

2) Cages, Safety Devices, and Controls 

a. The required pressure gage should 
be installed so that it is visible from 
the operating area located in such 
a way that the operator can accu- 
rately determine the pressure in the 
vessel while it is in operation. The 
gage dial size should be of such a 
diameter that it can be easily read 
by the operator. This gage should 
have a pressure range of at least 1 - 
1/2 times, but not more than four 
times, the operating pressure of the 
vessel. There should be no interven- 
ing valve between the vessel and 
gage- 



fa. The pressure gage should be of a 
type that will give accurate read- 
ings, especially when there is a 
rapid change in pressure. It should 
be of rugged construction and 
capable of withstanding severe ser- 
vice conditions. Where necessary, 
the gage should be protected by a 
siphon or trap. 

c. Pressure gages intended to measure A07 
the operating pressure in the vessel 

are not usually sensitive or easily 
read at low pressures approaching 
atmospheric. It may be advisable to 
install an auxiliary gage that reads 
inches of water (mm of mercury) 
and is intended to measure pres- 
sure from atmospheric through low 
pressures. This gives assurance that 
there is zero pressure in the ves- 
sel before opening. It would be 
necessary to protect the auxiliary 
low pressure gage from the higher 
operating pressures. 

d. Provisions should be made to 
calibrate pressure gages or to have 
them checked against a master gage 
as frequently as necessary. 

e. A check should be made to ensure 
that the closure and its holding 
elements must be fully engaged in 
their intended operating position 
before pressure can be applied to 
the vessel. A safety interlock device 
should be provided that prevents 
the opening mechanism from oper- 
ating unless the vessel is completely 
depressurized. 

f. Quick-actuating closures held in 
position by manually operated 
locking devices or mechanisms, 
and which are subject to leakage of 
the vessel contents prior to disen- 
gagement of the locking elements 



44 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



2.4 



2.4.1 



and release of the closure, shall be 
provided with an audible and/or 
visible warning device to warn the 
operator if pressure is applied to 
the vessel before the closure and 
its holding elements arc fully en- 
gaged, and to warn the operator if 
an attempt is made to operate the 
locking device before the pressure 
within the vessel is released. Pres- 
sure tending to force the closure 
clear of the vessel must be released 
before the closure can be opened 
for access. 



PIPING AND PSPSNG SYSTEMS 



SCOPE 



This section provides guidelines for internal 
and external inspection of piping and piping 
systems. 



2.4.2 



SERVICE CONDITIONS 



a) Piping systems are designed for a variety of 
service conditions. The media that a piping 
system contains, the temperature at which 
it operates, and the piping corrosion history 
should be considered in establishing pip- 
ing inspection criteria. Particular attention 
should be given to piping systems that arc 
subject to corrosion, high temperatures, 
and hazardous fluid or gasses. Piping op- 
erating beyond design temperature limits 
can cause sufficient deterioration of piping 
material properties due to graphitization, 
embrittlement, and creep to render the 
piping system unfit for continued service. 

b) Any externally or internally corroded pip- 
ing should be evaluated for integrity and 
repaired or replaced as necessary. 

c) Requirements specified for inspection ac- 
tivities and safety is identified in Section 



1 of this Part and should be reviewed and 
followed as applicable. 



2.4.3 ASSESSMENT OF PIPING 

DESIGN 

a) All pipe material and fittings should be 
properly rated for the maximum service 
conditions to which they are subjected 
under normal operating conditions and A07 
shall be provided with suitable relief device 
protection. The design corrosion allowance 

of the piping system should be considered 
when reviewing the current piping thick- 
ness data. 

b) If a piping system has a previous history of 
ultrasonic wall thickness measurements, 
the Inspector should review the data and 
request additional wall thickness measure- 
ments, if warranted. 



2.4.4 EXTERNAL INSPECTION OF 

PIPING 

Piping should be externally inspected for the 
following: 

a) Evidence of leakage. (See 2.4.6) 

b) Provision for expansion and adequate sup- 
port. (See 2.4.7) 

c) Proper alignment of piping joints and bolted 
connections. Check for missing bolts or 
studs, nuts, and improper or inadequate 
bolted connection thread engagement. Also 
check visible gasket and gasket alignment 
condition. Threaded connections should 
also be inspected for inadequate or exces- 
sive thread engagement. 

d) Past or present evidence of excessive vibra- 
tion or cyclic activity such as loose or miss- 
ing piping supports or piping insulation. If 
such activity is present, piping and piping 
joints should be inspected for potential 
fatigue cracking. 



45 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



e) Evidence of general corrosion, excessive 
external pitting, corrosion scale buildup, 
exfoliation, erosion, cuts, dents, distortion, 
or other detrimental conditions such as 
pipe sweating, water hammer damage, or 
hot spots. Ultrasonic thickness measure- 
ments should be taken in suspect areas 
to ensure adequate remaining piping wall 
thickness. 

f) Evidence of corrosion under piping insula- 
tion or other weather related damage to 
piping coatings. 

g) Evidence of freeze damage such as bulging, 
striations, or surface fissures. 

h) Dead leg or stagnant piping tends to have 
internal corrosion issues. Ultrasonic thick- 
ness measurements should be taken in sus- 
pect locations. Radiography is also useful 
to assess internal deposits and subsequent 
corrosion in no flow piping locations. 



2.4.5 INTERNAL INSPECTION OF 

PIPING 

a) Where the internal surfaces of piping, 
valves, and gasket surfaces are accessible 
to visual examination, internal inspection 
should include an examination of all avail- 
able surfaces. Nondestructive examina- 
tion for internal corrosion may be used to 
supplement the inspection. Boroscope or 
camera inspections are also useful to aug- 
ment piping internal inspections. 

b) Internal pipe surfaces should be cleaned 
before inspection, if necessary. 

c) The internal surfaces of piping, piping 
welds, and connections, fittings, valves, 
and gasket surfaces should be inspected for 
localized corrosion, pitting, erosion, blister- 
ing, cracking, and impingement damage. 



2.4.6 



EVIDENCE OF LEAKAGE 



a) A leak should be thoroughly investigated 
and corrective action initiated. Leaks 
beneath piping insulation should be ap- 
proached with caution, especially when 
removing insulation from a pressurized 
piping system for inspection. 

b) A pressure test may be required to obtain 
additional information regarding the extent 
of a defect or detrimental condition. 

c) To determine tightness, the test pressure 
need be no greater than the normal operat- 
ing pressure. The metal temperature should 
be not less than 70°F (21 C C) and the maxi- 
mum metal temperature during inspection 
should not exceed 12()°F (49°C). The po- 
tential corrosive effect of the test fluid on 
the piping material should be considered. 



2.4.7 PROVISIONS FOR EXPANSION 

AND SUPPORT 

a) Visual inspection should include a check 
for evidence of improper provision for 
piping expansion and support. Piping 
supports shall indicate loads within their 
design range. Piping supports should keep A07 
piping in alignment and prevent piping 
from colliding with other piping or station- 
ary objects. The alignment of connections 
between anchored equipment should be 
observed to determine if any change in po- 
sition of the equipment due to settling, ex- 
cessive cyclic activity, steady state stresses 
beyond design al lowances, or other causes 
has placed an undue strain on the piping or 
its connections. Inadequate support or the 
lack of provision for expansion may cause 
broken attachment welds, cracks, or leak- 
age at fittings. Missing, damaged, or loose 
insulation materials may be an indication 
of vibration or pipe movements resulting 
from improper support. 



46 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



b) Piping support locations should be closely 
inspecled at the support points for external 
and crevice corrosion concerns. 



2.4.8 



2.4.8.1 



INSPECTION OF GAGES, 
SAFETY DEVICES, AND 
CONTROLS 



GAGES 



Piping system pressure gages should be re- 
moved for testing unless there is other informa- 
tion to assess their accuracy. Faulty pressure 
gages should be recalibrated or replaced as 
necessary. 



2.4.8.2 SAFETY DEVICES 

See 2.5 for information on the inspection of 
pressure-relieving devices used to prevent the 
over pressure of piping systems. 



2.4.8.3 QUICK-DISCONNECT 
COUPLING 

Piping connections utilizing a quick-disconnect 
coupling should be checked to ensure that the 
coupling and its holding elements are fully- 
engaged in their intended operating position. 
Means should be provided that warn the opera- 
tor against disengaging the coupling or prevent 
the opening mechanism from operating unless 
the piping is completely depressurized. 



2.5 



2.5.1 



PRESSURE RELIEF DEVICES 



SCOPE 



The most important appurtenances on any 
pressurized system are the pressure relief 
devices provided for overpressure protec- 
tion of that system. These are devices such 
as safety valves, safety relief valves, pilot 



valves, and rupture disks or other non- 
reclosing devices that are called upon to 
operate and reduce an overpressure condi- 
tion. 

b) These devices are not designed or intended 
to control the pressure in the system dur- 
ing normal operation. Instead, they are in- 
tended to function when normal operating 
controls fail or abnormal system conditions 
are encountered. 

c) Periodic inspection and maintenance of 
these important safety devices is critical to 
ensure their continued functioning and to 
provide assurance that they will be avail- 
able when called upon to operate. See 
2.5.8 for recommended testing frequency 
for PRDs. 

d) Inspection areas of concern include: 

1) correct set pressure; A07 

2) safety considerations; 

3) device data; 

4) condition of the device; 

5) condition of the installation; and 

6) testing and operational inspection. 



2.5.2 



PRESSURE RELIEF DEVICE DATA 



a) Nameplate marking or stamping of the 
device should be compared to stamping 
on the protected pressure-retaining item. 
For a single device, the set pressure shall 
be no higher than the maximum allowable 
working pressure (MAWP) marked on the 
protected pressure-retaining item or sys- 
tem. 

b) If multiple devices are provided, the differ- 
ence between set pressures shall not ex- 
ceed that permitted by the original code of 



4-7 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



construction. The set pressure of additional 
devices may exceed the MAWP, as permit- 
ted by the original code of construction. 

c) Verify nameplate capacity and, if pos- 
sible, compare to system capacity require- 
ments. 

d) Check identification on seals and ensure 
they match nameplates or other identifica- 
tion (repair or reset nameplate) on the valve 
or device. 



A08 2.5.3 INSERVICE INSPECTION 

REQUIREMENTS FOR PRESSURE 
RELIEF DEVICE CONDITIONS 

a) Check for evidence that the valve or device 
is leaking or not sealing properly. 

b) Seals for adjustments should be intact and 
show no evidence of tampering. 

c) Connecting bolting should be tight and all 
bolts intact. 

d) The valve or device should be examined 
for deposits or material buildup. 

e) Evidence of rust or corrosion should be 
checked. 

f) Check for damaged or misapplied parts. 

g) If a drain hole is visible, ensure it is not 
clogged with debris or deposits. 

h) Check for test gags left in place after pres- 
sure testing of the unit. 

i) Bellows valves shall be checked to ensure 
the bonnet vent is open or piped to a safe 
location. The vent shall not be plugged 
since this will cause the valve set pressure 
to be high if the bellows develops a leak. 
Leakage noted from the vent indicates the 
bellows is damaged and will no longer 
protect the valve from the effects of back 
pressure. 



2.5.4 INSERVICE INSPECTION A07 

REQUIREMENTS FOR PRESSURE A08 
RELIEF DEVICES INSTALLATION 
CONDITION 

a) Inspect inlet piping and ensure it meets the 
requirements of the original code ol con- 
struction. For pressure relief valves, check 
that the inlet pipe size is not smaller than 
the device inlet size. 

b) Inspect discharge piping and ensure it 
meets the original code of construction. 
Check that the discharge pipe size is not 
smaller than the device outlet size. 

c) Check that the valve drain piping is open. 

d) Check drainage of discharge piping. 

e) Check that inlet and discharge piping are 
not binding or placing excessive stress on 
the valve body which can lead to distortion 
of the valve body and leakage or malfunc- 
tion. 

f) Check the condition and adequacy of 
piping supports. Discharge piping should 
be supported independent of the device 
itself. 

g) Check for possible hazards to personnel 
from the valve discharge or discharge 
pipe. 

h) Check that there are no intervening isola- 
tion valves between the pressure source 
and the valve inlet or between the valve 
outlet and its point of discharge. (Isolation 
valves may be permitted in some pressure 
vessel service. See Part 1, 5.3.6 e), and ju- 
risdictional requirements. Isolation valves 
are not permitted for power boilers, heating 
boilers, or water heaters.) 

i) A change-over valve, which is used to in- 
stall two pressure relief devices on a single 
vessel location for the purpose of switching 
from one device to a spare device, is not 
considered a block valve if it is arranged 



48 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



7) The frequency of inspection for rupture 
disks and other non-reclosing devices is 
greatly dependent on the nature of the 
contents and operation of the system 
and only general recommendations can 
be given. Inspection frequency should 
be based on previous inspection history. 
If devices have been found to be leak- 
ing, defective, or damaged by system 
contents during inspection, intervals 
should be shortened until acceptable 
inspection results are obtained. With 
this in mind, the inspection frequency 
guidelines specified in 2.5.8 are sug- 
gested for similar services. 

8) Rupture disks are often used to isolate 
pressure relief valves from services 
where fouling or plugging of the valve 
inlet occurs. This tendency should be 
considered in establishing the inspec- 
tion frequency. 

9) Since these devices are for one time 
use, a visual inspection is the only 
inspection that can be performed. 
Rupture disks that are installed using 
a specified bolting torque procedure 
cannot be reused after inspection and 
must be replaced. 

A08 1 0) It is recommended that all rupture disks 
be periodically replaced to prevent un- 
intended failure while in service due to 
deterioration of the device. 

Rupture disks should be carefully 
checked for damage prior to installa- 
tion and handled by the disk edges, if 
possible. Any damage to the surface of 
the ruptured disk can affect the burst 
pressure. 

A08 2.5.6 PACKAGING, SHIPPING AND 

TRANSPORATION 

A08 a) The improper packaging, shipment and 
transport of pressure relief devices can 
have detrimental effects on device op- 
eration. Pressure relief devices should 
be treated with the same precautions as 



instrumentation, with care taken to avoid 
rough handling or contamination prior to 
installation. 

b) The following practices are recommended: 

1) Valves should be securely fastened to A08 
pallets in the vertical position to avoid 
side loads on guiding surfaces except 
threaded and socket-weld valves up to 

2 in. (50mm) may be securely packaged 
and cushioned during transport. 

2) Valve inlet and outlet connection, drain A08 
connections, and bonnet vents should 

be protected during shipment and stor- 
age to avoid internal contamination of 
the valve. Ensure all covers and/or plugs 
are removed prior to installation. 

3) Lifting levers should be wired or se- A08 
cured so they cannot be moved while 

the valve is being shipped or stored. 
These wires shall be removed before 
the valve is placed in service. 

4) Pilot valve tubing should be protected A08 
during shipment and storage to avoid 
damage and/or breakage. 

2.5.7 TESTING AND OPERATIONAL 

INSPECTION OF PRESSURE 
RELIEF DEVICES 

a) Pressure relief valves must be periodically test- 
ed to ensure that they are free to operate and 
will operate in accordance with the require- 
ments of the original code of construction. 
Testing should include device set or opening 
pressure, reclosing pressure, where appli- 
cable, and seat leakage evaluation. Tolerances 
specified for these operating requirements in 
the original code of construction shall be used 
to determine the acceptability of test results. 

b) Testing may be accomplished by the owner 
on the unit where the valve is installed or 
at a qualified test facility. In many cases, 
testing on the unit may be impractical, es- 
pecially if the service fluid is hazardous or 
toxic. Testing on the unit may involve the 



51 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



bypassing of operating controls and should 
only be performed by qualified individuals 
under carefully controlled conditions. It is 
recommended that a written procedure be 
available to conduct this testing. 

1) The Inspector should ensure that 
calibrated equipment has been used to 
perform this test and the results should 
be documented by the owner. 

2) If the testing was performed at a test 
facility, the record of this test should 
be reviewed to ensure the valve meets 
the requ i rements of the origi na I code of 
construction. Valves which have been 
in toxic, flammable, or other hazardous 
services shall be carefully decontami- 
nated before being tested. In particular, 
the closed bonnet of valves in these 
services may contain fluids that are not 
easily removed or neutralized. If a test 
cannot be safely performed, the valve 
shall be disassembled, cleaned, and 
decontaminated, repaired, and reset. 

3) If a valve has been removed for testing, 
the inlet and outlet connections should 
be checked for blockage by product 
buildup or corrosion. 

c) Valves may be tested using lift assist de- 
vices when testing at full pressure may 
cause damage to the valve being tested, 
or it is impractical to test at full pressure 
due to system design considerations. Lift 
assist devices apply an auxiliary load to 
the valve spindle or stem, and using the 
measured inlet pressure, applied load and 
other valve data allow the set pressure to be 
calculated. If a lift assist device is used to 
determine valve set pressure, the conditions 
of Part 3, Repairs and Alterations, Section 
4.5.3 shall be met. It should be noted that 
false set pressure readings may be obtained 
for valves which are leaking excessively or 
otherwise damaged. 



d) If valves are not tested on the system using 
the system fluid, the following test mediums 
shall be used: 

1 ) High pressure boiler safety valves, high 
temperature hot-water boiler safety re- 
lief valves, low pressure steam heating 
boilers: steam; 

2) Hot-water heating boiler safety relief 
valves: steam, air, or water; 

3) Hot water heater temperature and pres- 
sure relief valves: air or water; 

4) Air and gas service process safety relief 
valves: air, nitrogen, or other suitable 
gas; 

5) Liquid service process pressure relief 
valves: water or other suitable fluid; 

6) Process steam service safety relief 
valves: steam or air with manufacturer's 
steam to air correction factor. 

Note: Valves being tested after a repair 
must be tested on steam except as 
permitted by Part 3, Repairs and Altera- 
tions, Section 4.5.2. 

e) As an alternative to a pressure test, the valve 
may be checked by the owner for freedom 
of operation by activating the test or "try" 
lever (manual check). For high pressure 
boiler and process valves this test should 
be performed only at a pressure greater 
than 75% of the stamped set pressure of the 
valve or the lifting device may be damaged. 
This test will only indicate that the valve is 
free to operate and does not provide any 
information on the actual set pressure. All 
manual checks should be performed with 
some pressure under the valve in order to 
flush out debris from the seat that could 
cause leakage. 



52 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



Note: The manual check at 75% or higher 
is based on lift lever design requirements 
for ASME Section I and VIM valves. Code 
design requirements for lifting levers for 
Section IV valves require that the valve be 
capable of being lifted without pressure. 

f) If a valve is found to be stuck closed, the 
system should immediately be taken out 
of service until the condition can be cor- 
rected, unless special provisions have been 
made to operate on a temporary basis (such 
as additional relief capacity provided by 
another valve). 

g) If a pressure test indicates the valve does 
not open within the requirements of the 
original code of construction, but otherwise 
is in acceptable condition, minor adjust- 
ments (defined as no more than twice the 
permitted set pressure tolerance) shall be 
made by an organization accredited by the 

A07 National Board to reset the valve to the 
correct opening pressure. All adjustments 
shall be resealed with a seal identifying the 
responsible organization and a tag shall be 
installed identifying the organization and 
the date of the adjustment. 

h) If a major adjustment is needed, this may 
indicate the valve is in need of repair or has 
damaged or misapplied parts. Its condition 
should be investigated accordingly. 

i) Systems with multiple valves will require 
the lower set valves to be held closed to 
permit the higher set valves to be tested. 
A test clamp or "gag" should be used 
for this purpose. The spring compression 
screw shall not be tightened. It is recom- 
mended that the test clamps be applied in 
accordance with the valve manufacturer's 
instructions when the valve is al or near the 
test temperature, and be applied hand tight 
only to avoid damage to the valve stem or 
spindle. 

j) Upon completion of set pressure testing, 
all pressure relief valve gags shall be re- 
moved. 



2.5.8 RECOMMENDED INSPECTION A07 

AND TEST FREQUENCIES FOR 
PRESSURE RELIEF DEVICES 

a) Power Boilers 

1 ) Pressure less than 400 psig (2.76 MPa): 
Manual check every 6 months; pressure 
test annually to verify nameplate set 
pressure or as determined by operat- 
ing experience as verified by testing 
history. 

2) Pressure greater than 400 psig (2.76 
MPa): Pressure test to verify nameplate 
set pressure every three years or as 
determined by operating experience as 
verified by testing history. 

3) Pressure tests should be performed prior 
to bringing the boiler down for planned 
internal inspection so needed repairs 
or adjustments can be made while the 
boiler is down. 

b) High-Temperature Hot-Water Boilers 
Pressure test annually to verify nameplate 
set pressure or as determined by operating 
experience as verified by testing history. 
For safety reasons, removal and testing on 
a steam test bench is recommended. Such 
testing will avoid damaging the safety valve 
by discharge of a steam water mixture, 
which could occur if the valve is tested in 
place. 

c) Low-Pressure Steam Heating Boilers 
Manual check quarterly; pressure test annu- 
ally prior to steam heating season to verify 
nameplate set pressure. 

d) Hot-Water Heating Boilers 

Manual check quarterly; pressure test an- 
nually prior to heating season to verify 
nameplate set pressure. 

Note: The frequencies specified for the 
testing of pressure relief valves on boilers 
is primarily based on differences between 
high pressure boilers that are continuously 



53 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



e) 



manned, and lower pressure automatically 
controlled boilers that are not monitored 
by a boiler operator at all times. When 
any boiler experiences an overpressure 
condition such that the safety or safety 
relief valves actuate, the valves should be 
inspected for seat leakage and other dam- 
age as soon as possible and any deficiencies 
corrected. 

Water Heaters 

Manual check every two months. Due to 
the relatively low cost of safety valves for 
this service, it is recommended that a defec- 
tive valve be replaced with a new valve if 
a repair or resetting is indicated. 

Pressure Vessels and Piping 
Frequency of test and inspection of pres- 
sure relief devices for pressure vessel and 
piping service is greatly dependent on the 
nature of the contents and operation of the 
system and only general recommendations 
can be given. Inspection frequency should 
be based on previous inspection history. If 
valves are found to be defective or damaged 
by system contents during inspection, inter- 
vals should be shortened until acceptable 
inspection results are obtained. Where test 
records and/or inspection history are not 
available, the following inspection and test 
frequencies are suggested. 



determine and agree on a suitable interval 
for inspection and test. Some items to be 
considered in making this determination 



Service Inspection Frequency 


Steam 


Annual 


Air and Clean Dry 
Cases 


Every three years J 


Pressure relief valves 
in combination with 
rupture disks 


Every five years ! 


Propane, Refrigerant 


Every five years 


All Others 


Per inspection history | 



g) Establishment of Inspection and Test Inter- 
vals 

Where a recommended test frequency is 
not listed, the valve user and Inspector must 



are: 

1) Jurisdictional requirements; 

2) Records of test data and inspections 
from similar processes and similar de- 
vices in operation at that facility; 

3) Recommendations from the device 
manufacturer. In particular, when the 
valve includes a non-metallic part such 
as a diaphragm, periodic replacement 
of those parts may be specified; 

4) Operating history of the system. Sys- 
tems with frequent upsets where a valve 
has actuated require more frequent 
inspection; 

5) Results of visual inspection of the de- 
vice and installation conditions. Signs 
of valve leakage, corrosion or damaged 
parts all indicate more frequent opera- 
tional inspections; 

6) Installation of a valve in a system with 
a common discharge header. Valves 
discharging into a common collection 
pipe may be affected by the discharge 
of other valves by the corrosion of parts 
in the outlet portion of the valve or the 
buildup of products discharged from 
those valves; 

7) Ability to coordinate with planned 
system shutdowns. The shutdown of 
a system for other maintenance or in- 
spection activities is an ideal time for 
the operational inspection and test of 
a pressure relief valve; 

8) Critical nature of the system. Systems 
that are critical to plant operation or 
where the effects of the discharge of 
fluids from the system are particularly 



54 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



detrimental due to fire hazard, environ- 
mental damage, or toxicity concerns 
all call for more frequent inspection 
intervals to ensure devices are operat- 
ing properly; 

9) Where the effects of corrosion, block- 
age by system fluid, or ability of the 
valve to operate under given service 
conditions are unknown (such as in 
a new process or installation), a rela- 
tively short inspection interval, not to 
exceed one year or the first planned 
shutdown, whichever is shorter, shall 
be established. At that time the device 
shall be visually inspected and tested. If 
unacceptable test results are obtained, 
the inspection interval shall be reduced 
by 50% until suitable results are ob- 
tained. 



3) 



also well advised preventative mainte- 
nance activities that can prevent future 
problems. If the valve is serviced, a 
complete disassembly, internal inspec- 
tion, and repair as necessary, such that 
the valve's condition and performance 
are restored to a like new condition, 
should be done by an organization ac- 
credited by the National Board. A07 

Service records with test results and 
findings should be maintained for all 
over pressure protection devices. A 
service interval of no more than three 
inspection intervals or ten years, which- 
ever is less, is recommended to main- 
tain device condition. Results of the 
internal inspection and maintenance 
findings can then be used to establish 
future service intervals. 



h) Establishment of Service Intervals 

1) The above intervals are guidelines for 
periodic inspection and testing. Typi- 
cally if there are no adverse findings, a 
pressure relief valve would be placed 
back in service until the next inspec- 
tion. Any unacceptable conditions 
that are found by the inspection shall 
be corrected immediately by repair or 
replacement of the device. Many us- 
ers will maintain spare pressure relief 
devices so the process or system is not 
affected by excessive downtime. 

2) Pressure relief valves are mechanical 
devices that require periodic preven- 
tive maintenance even though external 
inspection and test results indicate ac- 
ceptable performance. There may be 
wear on internal parts, galling between 
sliding surfaces or internal corrosion, 
and fouling which will not be evident 
from an external inspection or test. 
Periodic re-establishment of seating sur- 
faces and the replacement of soft goods 
such as O-rings and diaphragms are 



55 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



56 




Part 2, Section 3 

Inspection — Corrosion and Failure 

Mechanisms 



57 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



INSPECTION 



PART 2, SECTION 3 
CORROSION AND FAILURE MECHANISMS 



3.1 SCOPE 

A07 a) This section describes damage mechanisms 
applicable to pressure-retaining items. Further 
information concerning metallurgical properties 
of steels and nonferrous alloys are described in 
ASME Section II, Rart D, of the Boiler and Pres- 
sureVessel Code, Non Mandatory Appendix A, 
titled Metallurgical Phenomena. 

A07 b) A damage (or deterioration) mechanism is a 
process that induces deleterious micro and 
or macro material changes over time that 
are harmful to the material condition or me- 
chanical properties. Damage mechanisms 
are usually incremental, cumulative and, in 
some instances, unrecoverable. Common 
damage mechanisms include corrosion, 
chemical attack, creep, erosion, fatigue, 
fracture, and thermal aging. 



A07 3.2 



GENERAL 



Understanding the potential damage/deteriora- 
tion mechanisms that can affect the mechani- 
cal integrity of a pressure-retaining item and 
knowledge of the inspection methods that can 
be used to find these damage mechanisms are 
essential to an effective inspection. This sec- 
tion includes a general discussion of various 
damage mechanisms and effective inspection 
methods are referenced in Section 4 of this Part. 
In addition, some specific guidance is given on 
how to estimate the remaining life of a pressure- 
retaining item and determine the appropriate 
inspection frequencies as referenced in Section 
5 of this Part. 



3.3 



CORROSION 



All metals and alloys are susceptible to cor- 
rosion. Corrosion is deterioration that occurs 



when a metal reacts with its environment. 
Corrosion can be classified based on three 
factors: 

a) Nature 

1 ) wet — liquid or moisture present 

2) dry — high temperature gasses 

b) Mechanism — electrochemical or direct 
chemical reactions 

c) Appearance — either uniform or local- 
ized 



3.3.1 MACROSCOPIC CORROSION 

ENVIRONMENTS 

Macroscopic corrosion types are among the 
most prevalent conditions found in pressure- 
retaining items causing deterioration. The fol- 
lowing corrosion types are found. 

a) Uniform Corrosion (General) 

The most common form of corrosion is 
uniform attack over a large area of the 
metal surface. Safe working pressure is 
directly related to the remaining material 
thickness, and failures can be avoided by 
regular inspection. 

b) Galvanic Corrosion 

Two dissimilar metals in contact with each 
other and with an electrolyte (i.e., a film 
of water containing dissolved oxygen, 
nitrogen, and carbon dioxide) constitute 
an electrolytic cell, and the electric cur- 
rent flowing through the circuit may cause 
rapid corrosion of the less noble metal (the 
one having the greater electrode potential). 
This corrosion mechanism is most active 
when there are large differences between 



58 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



the electrode potentials of the two metals, 
but galvanic corrosion may also exist with 
relatively minor changes of alloy compo- 
sition (i.e., between a weld metal and the 
base metal). Natural (i.e., an oxide coating 
on aluminum) or protective coatings may 
inhibit galvanic corrosion, but in most 
instances the metals or alloys must be se- 
lected on the basis of intrinsic resistance 
to corrosion. In pressure vessels the effects 
of galvanic corrosion are most noticeable 
at rivets, welds, or at flanged and bolted 
connections. 

c) Erosion Corrosion 

Movement of a corrosive over a metal 
surface increases the rate of attack due to 
mechanical wear and corrosion. This cor- 
rosion is generally characterized as having 
an appearance of smooth bottomed shal- 
low pits and may also exhibit a directional 
pattern related to the path taken by the 
corrosive. 

d) Crevice Corrosion 

Environmental conditions in a crevice can, 
with time, become different to those on a 
nearby clean surface. A more aggressive en- 
vironment may develop within the crevice 
and cause local corrosion. Crevices com- 
monly exist at gasket surfaces, lap joints, 
bolts, rivets, etc. They are also created by 
dirt deposits, corrosion products, scratches 
in paint, etc. Crevice corrosion is usually at- 
tributed to one or more of the following: 

1) Changes in acidity in the crevice; 

2) Lack of oxygen in the crevice; 

3) Buildup of detrimental ions in the crev- 
ice; and 

4) Depletion of a corrosion inhibitor in 
the crevice. 

e) Pitting Corrosion 

Pitting corrosion is the formation of holes in 
an otherwise relatively unattacked surface. 



Pitting is usually a slow process causing 
isolated, scattered pitting over a small area 
that does not substantially weaken the ves- 
sel. It could, however, eventually cause 
leakage. 

f) Line Corrosion 

This is a condition where pits are con- 
nected, or nearly connected, to each other 
in a narrow band or line. Line corrosion 
frequently occurs in the area of intersection 
of the support skirt and the bottom of the 
vessel or liquid-vapor interface. 

g) Exfoliation 

Exfoliation is a subsurface corrosion that 
begins on a clean surface but spreads 
below it. It differs from pitting in that the 
attack has a laminated appearance. These 
attacks are usually recognized by a flaky 
and sometimes blistered surface. 

h) Selective Leaching 

Selective leaching is the removal of one ele- 
ment in an alloy. This corrosion mechanism 
is detrimental because it yields a porous 
metal with poor mechanical properties. 

i) Grooving 

This type of corrosion is a form of metal 
deterioration caused by localized cor- 
rosion and may be accelerated by stress 
concentration. Grooving may be found 
adjacent to riveted lap joints or welds and 
on flanged surfaces, particularly the flanges 
of un-stayed heads. 



3.3.2 MICROSCOPIC CORROSION 

ENVIRONMENTS 

Microscopic corrosion environments are not 
visible to the naked eye. The following cor- 
rosion types are among the most prevalent 
conditions found in pressure-retaining items 
causing deterioration. 

a) Intergranular Corrosion 

Corrosion attack by a corrosive usually re- 
lated to the segregation of specific elements 



53 



NATIONAL BOARD INSPECTION CDDE • PART 2 — INSPECTION 



A07 



or the formation of a compound in the 
grain boundary. It usually attacks the grain 
boundary that has lost an element neces- 
sary for adequate corrosion resistance. In 
severe cases entire grains are dislodged 
causing the surface to appear rough to the 
naked eye and will feel sugary because 
of the loose grains. Susceptibility to inter- 
granular corrosion is usually a by-product 
of heat treatment. 

b) Stress Corrosion Cracking (SCC) 



1) The action of tensile stress and a cor- 
rosive result in the cracking of metals. 
This is most serious because periods 
of time (often years) may pass before 
cracks become visible. The cracks then 
propagate quite rapidly and result in 
unexpected failures. Stresses that cause 
cracking arise from cold working, 
welding, thermal treatment, or may 
be externally applied during service. 
The cracks can follow intergranular or 
transgranular paths and often have a 
tendency for branching. 

2) The principal variables affecting stress 
corrosion cracking are tensile stress, 
service temperature, solution chem- 
istry, (juration of exposure, and metal 
properties. Modifying any one of these 
parameters sufficiently can reduce or 
eliminate the possibility of stress corro- 
sion cracking occurring in service. As 
an example, austenitic stainless steels 
used in water wetted service are sus- 
ceptible to stress corrosion cracking. 

c) Corrosion Fatigue 

This is a special form of stress corrosion 
cracking caused by repeated cyclic stress- 
ing. When fatigue is in the presence of a 
corrodent, the result is corrosion fatigue. 
Such damage is common to pressure- 
retaining items subjected to continuous 
vibration. 

d) Microbiologically Induced Corrosion 
A08 Microbiologically induced corrosion (MIC) 

is caused by bacteria, algae or fungi and 



is often associated with the presence of 
tubercles or slimy organic substances. MIC 
is usually found in services where; stagnant 
water is present. 



3.3.3 



CONTROL OF CORROSION 



There are many ways to control and avoid 
corrosion such as control of process variables, 
engineering design, protection, material selec- 
tion, and coatings. 



3.3.3.1 PROCESS VARIABLES 

Some of the more common process variables 
that influence corrosion are listed below: 

a) Concentration of major constituents 

b) Impurities 

c) Temperature 

d) pH 

e) Velocity 

f) Inhibitors 

g) Start-up and downtime operations 



3.3.3.2 



PROTECTION 



Protective methods such as cathodic and an- 
odic corrosion control can minimize attack and 
thereby reduce replacement costs or permit the 
use of less expensive or thinner materials. 



3.3.3.3 



MATERIAL SELECTION 



Chemical and physical properties of a mate- 
rial will enable selection of the best one for a 
specific application. The final choice will often 
be a compromise between the desired physical 
properties and economic factors. A checklist for 
material selection would include: 



6D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



a) Fvaluating requirements to be met (prop- 
erties, design, appearance, mechanical, 
physical) 

b) Material selection considerations 

c) Corrosive variables 

d) Application of equipment 

e) Experience of materials 

3.3.3.4 COATINGS 

Metallic and inorganic materials are typical 
coatings for controlling corrosion. Selection 
of materials depends on the corrosive, method 
of application, type of base material, and the 
nature of bonding between the base material 
and coating. The success or failure of a coating 
will often depend on the surface preparation. 

a) Techniques for applying metallic coatings 
could include: 

1) Hot dipping 

2) Metal spraying 

3) Cladding 

4) Cementation 

5) Vapor deposition 

6) Electroplating 

7) Plating 

8) Welding 

b) Techniques for applying inorganic coatings 
would include: 

1) Porcelain, ceramic 

2) Glass 

3) Cement 



4) Rubber 

5) Paint 

6) Phosphates 



3.3.3.5 



ENGINEERING DESIGN 



Crevice, galvanic, erosion, and stress corro- 
sion cracking are the types of corrosion most 
controllable by proper design of equipment. 
Procedures and situations such as welding, end- 
grain attack, and drainage are also controlled 
by proper design techniques. 



3.3.3.6 



CONCLUSION 



a) By carefully selecting materials and protec- 
tion methods, we can predict and control 
corrosive attack. However, there may be 
unexpected damage as a result of one or 
more of the following: 

1) Poor choice of materials 

2) Operating conditions different from 
those anticipated 

3) Defective fabrication 

4) Improper design 

5) Inadequate maintenance 

6) Defective material 

b) Corrective actions will depend on which A07 
factors caused the problems making it im- 
portant to diagnose the reason for damage. 
Early detection of corrosion problems is 
important to prevent further damage and 
can be achieved by performing regular 
inspections and encouraging employees 

to be observant and communicate their 
observations. 



s i 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



3.4 



FAILURE MECHANISMS 



A07 The following failure mechanism information 
may assist inspectors in identifying service 
induced deterioration and failure modes en- 
countered in pressure-retaining items. 



3.4.1 



FATIGUE 



A07 Stress reversals (such as cyclic loading) in parts 
of equipment are common, particularly at 
points of high secondary stress. If stresses are 
high and reversals frequent damage may occur 
because of fatigue. Fatigue damage in pressure 
vessels may also result from cyclic temperature 
and pressure changes. Locations where metals 
having different thermal coefficients of expan- 
sion are joined by welding may be susceptible 
to thermal fatigue. 



3.4.2 



CREEP 



Creep damage may occur if equipment is 
subjected to temperatures above those for 
which the equipment is designed. Since metals 
become weaker at higher temperatures, such 
distortion may result in failure, particularly 
at points of stress concentration. If excessive 
temperatures are encountered, structural prop- 
erty and chemical changes in metals may also 
take place, which may permanently weaken 
equipment. Since creep is dependent on time, 
temperature and stress, the actual or estimated 
levels of these quantities should be used in any 
evaluations. 



3.4.3 



TEMPERATURE EFFECTS 



At subfreezing temperatures, water and some 
chemicals handled in pressure vessels may 
freeze and cause damage. Carbon and low al- 
loy steels may be susceptible to brittle failure 
at ambient temperatures. A number of failures 
have been attributed to brittle fracture of steels 
that were exposed to temperatures below their 



transition temperature and that were exposed 
to pressures greater than 20% of the required 
hydrostatic test pressure. However, most brittle 
fractures have occurred on the first applica- 
tion of a particular stress level (that is, the first 
hydrostatic test or overload). Special attention 
should be given to low alloy steels because 
they are prone to temper embrittlement. Temper 
embrittlement is defined as a loss of ductility 
and notch toughness due to postweld heat 
treatment or high temperature service, above 
700°F(371°C). 



3.4.4 



HYDROGEN EMBRITTLEMENT 



a) The term hydrogen embrittlement (HE) re- 
fers to a loss of ductility and toughness in 
steels caused by atomic hydrogen dissolved 
in the steel. Hydrogen that is dissolved in 
carbon and low alloy steels from steel mak- 
ing, welding, or from surface corrosion can 
cause either intergranular or transgranular 
cracking and "brittle" fracture behavior 
without warning. 

b) Hydrogen embrittlement typically occurs 
below 200°F (93°C) because hydrogen re- 
mains dissolved within the steel at or below 
this temperature. One example of hydrogen 
embrittlement is underbead cracking. The 
underbead cracks are caused by the ab- 
sorption of hydrogen during the welding 
process in the hard, high strength weld heat 
affected zone (HAZ). Use of low hydrogen 
welding practices to minimize dissolved 
hydrogen and/or the use of high preheat, 
and/or postweld heat treatment can reduce 
susceptibility to cracking from hydrogen 
embrittlement. The diffusivity of hydrogen 
is such that at temperatures above 450°F 
(232°C), the hydrogen can be effectively 
removed eliminating susceptibility to crack- 
ing. Thus, hydrogen embrittlement may be 
reversible as long as no physical damage 
(e.g., cracking or fissures) has occurred in 
the steel. 



62 



NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



c) Hydrogen embrittlement is a form of stress 
corrosion cracking (SCC). Three basic 
elements are needed to induce SCC: the 
first element is a susceptible material, the 
second element is environment, and the 
third element is stress (applied or residual). 
For hydrogen embrittlement to occur, the 
susceptible material is normally higher 
strength carbon or low alloy steels, the en- 
vironment must contain atomic hydrogen, 
and the stress can be either service stress 
and/or residual stress from fabrication. If 
any of the three elements are eliminated, 
HE cracking is prevented. 

d) In environments where processes are 
conducted at elevated temperature, the 
reaction of hydrogen with sulfur in carbon 
and low alloy reactor vessel steels can 
produce hydrogen sulfide stress corro- 
sion (SSC), which is a form of hydrogen 
embrittlement. Susceptibility to sulfide 
stress corrosion cracking depends on the 
strength of the steel. Higher strength steels 
are more susceptible. The strength level at 
which susceptibility increases depends on 
the severity of the environment. Hydrogen 
sulfide, hydrogen cyanide, and arsenic in 
aqueous solutions, all increase the sever- 
ity of the environment towards hydrogen 
embrittlement by increasing the amount 
of hydrogen that can be absorbed by the 
steel during the corrosion reaction. In hy- 
drogen sulfide environments, susceptibility 
to cracking can be reduced by using steels 
with a strength level below that equivalent 
to a hardness of 22 on the Rockwell C 
scale. 

e) Other forms of hydrogen embrittlement are 
wet hydrogen sulfide (H 2 S) cracking, hy- 
drogen stress cracking, hydrogen- induced 
cracking (HIC), and stress-oriented hydro- 
gen-induced cracking (SOHIC). In each 
case, three basic elements are required for 
this damage mechanism — susceptible ma- 
terial, hydrogen generating environments, 
and stress (either residual or applied). Or- 



ganic or inorganic coatings, alloy cladding 
or linings, are often used as a barrier to 
mitigate wet H 2 S corrosion and subsequent 
cracking. 



3.4.5 HIGH TEMPERATURE 

HYDROGEN ATTACK 

a) Hydrogen attack is a concern primarily in 
refinery and petrochemical plant equip- 
ment handling hydrogen and hydrogen- 
hydrocarbon streams at temperatures above 
450°F (232°C) and pressure above 100 
psi (700 kPa). A guideline for selection of 
steels to avoid hydrogen attack is given in 
API Publication 941, "Steels for Hydro- 
gen Service at Elevated Temperatures and 
Pressures in Petrochemical Refineries and 
Petrochemical Plants." Also widely known 
as the "Nelson Curves," API 941 shows that 
the severity of hydrogen attack depends on 
temperature, hydrogen partial pressure, 
exposure time, and steel composition. 
Additions of chromium and molybdenum 
increase resistance to hydrogen attack. It 
is important to understand that hydrogen 
attack is different from hydrogen embrittle- 
ment, which is discussed in 3.4.4. 

b) Hydrogen attack occurs in a high tempera- 
ture, high pressure hydrogen environment 
that can degrade the mechanical strength 
of carbon and low alloy steels. The dam- 
age is caused by hydrogen permeating into 
the steel and reacting with carbon to form 
methane. Since carbon is an element that 
strengthens steel, its removal by the high 
temperature reaction with hydrogen causes 
the steel to lose strength. In addition, meth- 
ane can become trapped within the steel at 
high pressures, eventually forming bubbles, 
fissures (cracks), and/or blisters. 

c) Damage caused by hydrogen attack is 
preceded by an incubation period with 
no noticeable change in properties. After 
the incubation period, decarburization 



63 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



and/or blistering and t'issuring will occur. 
The length of the incubation period var- 
ies with service temperature, the partial 
pressure of hydrogen, and alloy content of 
the steel. Damage is reversible during the 
incubation period, during which no loss of 
mechanical properties will have occurred. 
Once permanent degradation begins, the 
damage is irreversible. 



3.4.6 



HYDROGEN DAMAGE 



b) 



Hydrogen damage has been encountered 
in steam boilers that operate in the high 
pressure range (1200 psi [8.27 MPa] or 
higher), with relatively high purity boiler 
feed water. In boilers, the mechanism of 
hydrogen damage is initiated by underde- 
posit corrosion on water-touched surfaces. 
During operation of the boiler, waterwall 
tubing exposed to high heat flux can result 
in a departure from nucleate boiling (DNB) 
condition on the If) (waterside) surface due 
to small flow disturbances. Because of the 
increased tube metal temperature, low lev- 
els of contaminants in the boiler feedwater 
precipitate (e.g., plate out) on the hot tube 
surface. The intermittent wetting from flow, 
over time, results in the accumulation of 
deposits. 

As the deposit begins to thicken, the tube 
metal beneath the deposit locally increases 
in temperature causing oxidation of the 
tube metal. The oxidation/reduction corro- 
sion mechanism creates atomic hydrogen 
which permeates into the tube wall at boiler 
pressures greater than 1200 psig (8.27 
MPa). 

The atomic hydrogen reacts with the car- 
bon in the steel forming methane gas that 
results in microfissures at grain boundaries 
and decarburization. The combination of 
decarburization and microcracks increases 
the susceptibility to brittle fracture in ser- 
vice. The typical appearance of hydrogen 



damage in boiler tubes is a thick-lipped, 
"window-type" blow out of tube metal. 

d) Hydrogen damage in copper and copper 
alloys has also been observed and is some- 
times known as steam embrittlement. This 
type of damage commonly occurs when 
the copper contains oxygen. Hydrogen 
entering the metal reacts with the oxygen to 
form water. At certain combinations of pres- 
sures and temperatures steam forms and the 
pressure generated is sufficient to produce 
micro-cavity formation and cracking. 



3.4.7 



BULGES AND BLISTERS 



b) 



A bulge may be caused by overheating of 
the entire thickness of the metal, thereby 
lowering the strength of the metal which 
is then deformed by the pressure. Bulges 
may also be caused by creep or temperature 
gradients. 

A blister may be caused by a defect in the 
metal such as a lamination where the side 
exposed to the fire overheats but the other 
side retains its strength due to cooling effect 
of water or other medium. Blisters may also 
be caused by a hydrogen environment. (See 
3.4.5) 



3.4.8 



OVERHEATING 



a) Overheating is one of the most serious 
causes of deterioration. Deformation and 
possible rupture of pressure parts may re- 
sult. 

b) Attention should be given to surfaces that 
have either been exposed to fire, or exposed A07 
to operating temperatures that exceed their 
design limit. It should be observed whether 
any part has become deformed due to 
bulging or blistering. If a bulge or blister 
reduces the integrity of the component or 
when evidence of leakage is noted coming 
from those defects, proper repairs must be 
made. 



64 



NATIONAL BOARD INSPECTION CODE • PART 2 INSPECTION 



3.4.9 CRACKS 

a) Cracks may result from flaws existing in ma- 
terial or excessive cyclic stresses. Cracking 
can be caused by fatigue of the metal due 
to continual flexing and may be accelerated 

A07 by corrosion. Fire cracks are caused by the 
thermal differential when the cooling effect 
of the water is not adequate to transfer the 
heat from the metal surfaces exposed to the 
fire. Some cracks result from a combination 
of all these causes mentioned. 

b) Cracks noted in shell plates and fire cracks 
that run from the edge of the plate into the 
rivet holes of girth seams should be re- 
paired. Thermal fatigue cracks determined 
by engineering evaluation to be self arrest- 
ing may be left in place. 

c) Areas where cracks are most likely to ap- 
pear should be examined. This includes 
the ligaments between tube holes, from 
and between rivet holes, any flange where 
there may be repeated flexing of the plate 
during operation and around welded con- 
nections. 

d) Lap joints are subject to cracking where the 
plates lap in the longitudinal seam. If there 
is any evidence of leakage or other distress 
at this point, the Inspector shall thoroughly 
examine the area and, if necessary, have 
the plate notched or slotted in order to de- 
termine whether cracks exist in the seam. 
Repairs of lap joint cracks on longitudinal 
seams are prohibited. 

e) Where cracks arc suspected, it may be 
necessary to subject the pressure-retaining 
item to a hydrostatic test or nondestructive 
examination to determine their presence 
and location. 

A07 Cracks shall either be repaired, or formally 
evaluated by Crack Propagation Analysis to 
quantify their existing mechanical integ- 
rity. 



65 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



66 




Part 2, Section 4 
Inspection — Examinations, 
Test Methods, and Evaluations 



67 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



PART 2, SECTION 4 
INSPECTION — EXAMINATIONS, TEST METHODS, AND EVALUATIONS 



4.1 



SCOPE 



This section describes acceptable examination 
and test methods that arc available to the In- 
spector during inspection of pressure-retaining 
items. This section also describes evaluation of 
test results and assessment methodologies. 



4.2 NONDESTRUCTIVE 

EXAMINATION METHODS 
(NDE) 

a) Listed below is a variety of nondestruc- 
tive examination methods that may be 
employed to assess the condition of pres- 
sure-retaining items. The skill, experience, 
and integrity of the personnel performing 
these examinations are essential to obtain 
meaningful results. The Inspector should 
review the methods and procedures to be 
employed to assure compliance with juris- 
dictional requirements. 

b) Generally, some form of surface preparation 
will be required prior to use of these exami- 
nation methods. When there is doubt as to 
the extent of a defect or detrimental condi- 
tion found in a pressure-retaining item, the 
Inspector is cautioned to seek competent 
technical advice and supplemental NDE. 

A07 c) Personnel performing examination and test 
methods shall have proper training and cer- 
tification, as required by the owner and is 
acceptable to the Inspector and Jurisdiction, 
if required. 



A07 4.2.1 



VISUAL 



a) Visual examination is the basic method 
used when conducting an inservice inspec- 
tion of pressure-retaining items. Additional 



examination and test methods may be re- 
quired at the discretion of the inspector to 
provide additional information to assess the 
condition of the pressure-retaining item. 

b) Visual examination is an inspection method 
to ascertain the surface condition of the 
pressure-retaining item. The Inspector 
should be aware of recognizing various 
surface features and comparing these fea- 
tures with damage mechanisms listed in 
Section 3 of this Part that could indicate 
exposure of the pressure-retaining item to 
harmful corrosion or elevated temperature 
service. 

c) In some cases the Inspector may have 
limited or no access while performing an 
inspection of the pressure-retaining item. 
Subject to approval of the Jurisdiction, 
remote camera or fiber optic devices may 
be considered acceptable methods to view 
and record the surface condition of the 
pressure-retaining item. 



4.2.2 



MAGNETIC PARTICLE 



a) The magnetic particle examination method 
can be used only on ferromagnetic materi- 
als to reveal surface discontinuities and to 
a limited degree, those located below the 
surface. It uses the principle that magnetic 
lines of force will attract magnetizable 
material. The sensitivity of this method 
decreases rapidly with depth below the 
surface being examined and, therefore, it 
is used primarily to examine for surface 
discontinuities. 

b) In order to use this method, a magnetic field 
has to be established within the material to 
be examined. This can be done directly by 
bringing a strong magnetic field into close 



SB 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



c) If an inservice pressure test is required, the 
following precautions shall be met: 

1) The test pressure should not exceed 
90% of the set pressure of the lowest 
setting pressure relief device on the 
component to avoid damage to pres- 
sure relief devices. 

2) Test pressure should be selected or 
adjusted in agreement between the 
Inspector and the owner-user. When 
the original test pressure includes con- 
sideration of corrosion allowance, the 
test pressure may be further adjusted 
based upon the remaining corrosion 
allowance. 



4.3.2 



LEAK TESTING 



Leak testing lor the purpose of detecting any 
leakage may be performed when a pressure 
lesl cannot be performed. Some methods or 
techniques for leak testing may include bubble 
test (direct pressure or vacuum), helium mass 
spectrometer, pressure change, or flow mea- 
surement. Use of leak test procedures shall be 
in agreement between the owner-user and the 
Inspector. Use of written procedures and expe- 
rienced personnel is required when performing 
leak tests. The Inspector shall review the written 
procedure to become familiar with limitations, 
adequacy, methods, and acceptance standards 
identified. 



3) The metal temperature during a pres- 
sure test should not be less than 60°F 
(16°C) unless the owner-user provides 
information on the toughness character- 
istics of the vessel material to indicate 
the acceptability of a lower test tem- 
perature. 

4) The metal temperature shall not be 
more than 120°F (49°C) unless the 
owner-user specifies the requirement 
for a higher test temperature. If the 
owner-user specifies a test temperature 
higher than 1 20°r (49°Q, then precau- 
tions shall be taken to afford the Inspec- 
tor close examination without risk of 
injury. 

5) When contamination of the vessel 
contents by any medium is prohibited 
or when a pressure test is not practical, 
other testing methods described below 
may be used provided the precaution- 
ary requirements of the applicable 
Section of the original construction 
code or other standards are followed. 
In such cases, there shall be agreement 
as to the testing procedure between the 
owner-user and the Inspector. 



4.3.3 EVIDENCE OF LEAKAGE IN A 

BOILER 

For additional understanding regarding a leak 
in a boiler, see 2.2.7 for the extent of a pos- 
sible defect. A pressure test may be performed 
as follows: 

a) To determine tightness, the test pressure 
shall be no greater than the maximum al- 
lowable working pressure stamped on the 
pressure-retaining item. 

b) During a pressure test where the test pres- 
sure will exceed 90% of the set pressure of 
a pressure relief device, the device shall be 
removed whenever possible. If not possible 
or practical, a spindle restraint such as a 
gag may be used provided that the valve 
manufacturer's instructions and recom- 
mendations are followed. Extreme caution 
should be employed to ensure only enough 
force is applied to contain pressure. Exces- 
sive mechanical force applied to the spindle 
restraint may result in damage to the seat 
and/or spindle and may interfere with the 
proper operation of the valve. The spindle 
restraint shall be removed following the 
test. 



7 1 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



c) The organization who performs the pressure 4.4 
test and applies a spindle restraint shall 
attach a metal tag that identifies the orga- 
nization and date the work was performed 

to the pressure-relieving device. If the seal 

was broken, the organization shall reseal 

the adjustment housing with a seal that 4.4.1 

identifies the responsible organization. The 

process shall be acceptable to the Jurisdic- a) 

lion where the pressure-retaining items are 

installed. 

d) The temperature of the water used to ap- 
ply a pressure test should not be less than 
70°F (21 °C) and the maximum metal tem- 
perature during inspection shall not exceed 
120°F (49°C). A lower water temperature 
could be used if the owner can provide in- 
formation on the toughness characteristics 
of the material to indicate acceptability of 
the lower test temperature. 

e) Hold-time for the pressure test shall be 
for a minimum of 10 minutes prior to the 
examination by the Inspector. 

f) Hold-time for the examination by the 
Inspector shall be the time necessary for 
the Inspector to conduct the inspections. 

A07 Test pressure shall be maintained until the 
hydrostatic test is completed. 

g) When the introduction of water for a pres- 
sure test will cause damage to a boiler or 
boiler component, other testing media or 
vacuum testing may be used provided the b) 
precautionary requirements of the appli- 
cable section of the original code of con- 
struction or other standards are followed. 
In such cases, there shall be agreement as 
to the testing procedure between the owner 
and the Inspector. 



METHODS TO ASSESS DAMAGE 
MECHANISMS AND 
INSPECTION FREQUENCY FOR 
PRESSURE-RETAINING STEMS 



SCOPE 



This section provides guidelines and al- 
ternative methods to assess materials and 
pressure-retaining items subject to degrada- 
tion or containing flaws identified during 
inservice inspections or examinations. 
New pressure-retaining items are placed 
in service to operate within their intended 
design parameters for a period of time de- 
termined by service conditions, which can 
include exposure to corrosion, exposure to 
elevated temperature (creep), or other forms 
of damage. If the pressure-retaining item 
is to remain safe in operation, the service 
conditions and the length of time before the 
next inspection must be identified. There 
are various methods that can be used to 
assess the condition of a pressure-retain- 
ing item to establish remaining service life 
and to ultimately determine the inspection 
interval. In some cases, a visual inspection 
of the pressure-retaining item will suffice. 
However, more comprehensive condition 
assessment methods may be required, 
including an engineering evaluation per- 
formed by a competent technical source 
(see 5.3.2). 

Various assessment methods (see 1.3), 
including those mentioned in this Section 
(an example of guidelines for performing 
fitness for service assessments are refer- 
enced in API recommended practice API- 
579 "Fitness-for-Service"), can be used to 
establish the next inspection interval of a 
pressure-retaining item and to ensure safe 
operation. Condition assessment methods 
shall be subject to review and acceptance 
by the Jurisdiction. 



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NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



c) Safe and adequate implementation of 
Titness for Service Assessment (FFSA) pro- 
grams is the responsibility of the owner- 
user. Responsibility includes verifying and 
understanding jurisdictional rules/regula- 
tions and inservice inspection require- 
ments. Application of these programs may 
result in decisions that will deviate from or 
conflict with jurisdictional requirements 
(i.e., frequency or types of inspections, 
repairs and alterations, etc.). The Inspec- 
tor and Jurisdiction shall be contacted 
for acceptance, as appropriate, prior to 
implementing decisions that deviate from 
or conflict with established requirements. 

A07 d) If required by the Jurisdiction, FFSA shall be 
documented on a Report of FFSA Form NB- 
403, as shown in 5.3.7. Preparation of the 
Report of FFSA shall be the responsibility of 
the owner-user. An Inspector shall indicate 
acceptance by signing the Report of FFSA. 
Legible copies of the FFSA report shall 
be distributed to the Jurisdiction, and the 
Authorized Inspection Agency responsible 
for the inservice inspection. The owner-user 
shall maintain a copy of the FFSA report in 
the relevant equipment inspection history 
file. 



b) There are various condition assessment 
and fitness for service methods that can 
be used to determine inspection intervals, 
based on calculating the remaining service 
life of the pressure-retaining item. For items 
subject to corrosion or erosion, the method 
to determine or adjust inspection intervals 
is identified in 4.4.7. Methods for assessing 
other types of inservice damage that affect 
remaining service life of pressure-retaining 
items are identified in 4.4.8. 



4.4.3 



RESPONSIBILITIES 



a) Owner-User 

The owner-user of the pressure-retaining 
item is responsible for the selection and 
application of a suitable fitness for service 
or condition assessment methodology 
described in this section, subject to re- 
view and approval by the Jurisdiction, if 
required. 

b) Inspector 

The Inspector shall review the condition 
assessment methodology and ensure in- 
spection data and documentation arc in 
accordance with this section. 



4.4.2 



GENERAL REQUIREMENTS 



a) Organizations or qualified individuals with 
experience in inspection, design, construc- 
tion, repairs, or failure analysis of pressure- 
retaining items should be consulted to assist 
in identifying damage mechanisms, and 
to evaluate condition assessment results 
of pressure-retaining items. Documenta- 
tion and inspection data used for fitness 
for service assessment should be evalu- 
ated for compliance, with codes, industry 
standards/experience or good engineering 
practices, and shall be acceptable to the 
Jurisdiction. Understanding the operation 
of equipment or systems and interaction 
with their internal or external service en- 
vironment is necessary to correctly identify 
damage mechanisms. 



4.4.4 REMAINING SERVICE LIFE 

ASSESSMENT METHODOLOGY 

a) An evaluation of inservice damage using 
one or more condition assessment methods 
is not intended to provide a precise deter- 
mination of the actual time to failure for a 
pressure-retaining item. Instead, the extent 
of inservice damage should be estimated 
based on the quality of available informa- 
tion, established engineering assessment 
guidelines or methodology and appropriate 
assumptions used for safety, operation, and 
inspection. 

b) If inspection and engineering assessment 
results indicate that a pressure-retaining 
item is safe for continued operation, fu- 



73 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



ture monitoring and inspection intervals 
should be determined and submitted to 
the Jurisdiction for review and approval. If 
an engineering assessment indicates that 
a pressure-retaining item is not suitable 
for service under current operating condi- 
tions, new operating conditions should be 
established (i.e., de-rate), or the item could 
be repaired subject to revised inspection 
intervals, or the item could be replaced. 

c) Determination of the extent of inservice 
damage life requires the following: 

1 ) Understanding applicable damage and 
failure mechanisms; 

2) Developing inspection plans that can 
monitor the extent of inservice dam- 
age; 

3) Performing an assessment of the dam- 
age including estimation of remaining 
life; 

4) Considerations needed to minimize risk 
of failure; 

5) Determination of root cause; and 
A07 6) Corrective measures. 



4.4.5 DATA REQUIREMENTS FOR 

REMAINING SERVICE LIFE 

ASSESSMENTS 

Evaluating the extent of inservice damage to a 
pressure-retaining item requires an understand- 
ing of known and potential damage mecha- 
nisms. Information that can be used to evaluate 
service life can be divided into three categories: 
inspection history, operating and maintenance 
history, and equipment information. Examples 
of types of data are listed below: 

a) Inspeclion History 

1 ) Summary/records of Repairs and Altera- 
tions; 



2) Test Records including pressure tests; 

3) Results of prior inservice examinations 
(NDE methods, thickness measure- 
ments, and corrosion rate); and 

4) Physical measurements or inspec- 
tions. 

b) Operating History/Conditions 

1) Operating logs to include pressure, 
temperature, startups/shutdowns, 
cycles; 

2) Consult with operating personnel to 
determine operating history; 

3) Date of installation; 

4) Identify internal and external environ- 
mental conditions to include pressure, 
temperature, age, design, chemical and 
mechanical environment, loadings, 
processes, etc.; 

5) List damage mechanisms identified in 
the past and that may be present based 
on materials, contaminants, and operat- 
ing conditions; 

6) Identify the damage mechanisms pres- 
ently active or which may become ac- 
tive; and 

7) Identify the failure modes associated 
with the identified damage mecha- 
nisms, i.e., leaks, cracks, bursts, etc. 

c) Equipment Information 

1) Manufacturer's Data Reports 

2) Material Test Reports 

3) Drawings 

4) Original design calculations/specifica- 
tions 



74 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



the same material as the lining, ultrasonic 
examination, or radiography. To check 
the effectiveness of an internal insulation 
liner, melal temperatures may be obtained 
by surveying the pressure-retaining item 
with temperature measuring or indicating 
devices. 

e) Two or More Zones 

When a pressure-retaining item has two or 
more zones of pressure or temperature and 
the required thickness, corrosion allow- 
ance, or corrosion rate differ so much that 
the foregoing provisions give significant 
differences in maximum periods between 
inspections for the respective zones (e.g., 
the upper and lower portions of some 
fractionating towers), the period between 
inspections may be established individually 
for each zone on the basis of the condi- 
tion applicable thereto, instead of being 
established for the entire vessel on the basis 
of the zone requiring the more frequent 
inspection. 

f) Above-Ground Pressure Vessels 

All pressure vessels above ground shall 
be given an external examination after 
operating the lesser of five years, or one 
quarter of remaining life, preferably while 
in operation. Alternative intervals resulting 
in longer periods may be assigned pro- 
vided the requirements of this section have 
been followed. Inspection shall include 
determining the condition of the exterior 
insulation, the supports, and the general 
alignment of the vessel on its supports. 
Pressure vessels that are known to have a 
remaining life of over ten years or that are 
prevented from being exposed to external 
corrosion (such as being installed in a cold 
box in which the atmosphere is purged with 
an inert gas, or by the temperature being 
maintained sufficiently low or sufficiently 
high to preclude the presence of water), 
need not have the insulation removed for 
the external inspection. However, the con- 
dition of the insulating system and/or the 
outer jacketing, such as the cold box shell, 



shall be observed periodically and repaired 
if necessary. 

g) Interrupted Service 

1) The periods for inspection referred to 
above assume that the pressure-retain- 
ing item is in continuous operation, 
interrupted only by normal shutdown 
intervals. If a pressure-retaining item is 
out of service for an extended interval, 
the effect of the environmental condi- 
tions during such an interval shall be 
considered. 

2) If the pressure-retaining item was 
improperly stored, exposed to a detri- 
mental environment or the condition is 
suspect, it shall be given an inspection 
before being placed into service. 

3) The date of next inspection, which was 
established at the previous inspection, 
shall be revised if damage occurred dur- 
ing the period of interrupted service. 

h) Circumferential Stresses 

For an area affected by a general corrosion 
in which the circumferential stresses govern 
the MAWP, the least thicknesses along the 
most critical plane of such area may be 
averaged over a length not exceeding: 

1 ) The lesser of one-half the pressure ves- 
sel diameter, or 20 in. (500 mm) for 
vessels with inside diameters of 60 in. 
(1 .5 m) or less, or 

2) The lesser of one-third the pressure ves- 
sel diameter, or 40 in. (1 m), for vessels 
with inside diameters greater than 60 in. 
(1 .5 m), except that if the area contains 
an opening, the distance within which 
thicknesses may be averaged on either 
side of such opening shall not extend 
beyond the limits of reinforcement as 
defined in the applicable Section of the 
ASME Code for ASMF_ Stamped vessels 
and for other vessels in their applicable 
codes of construction. 



77 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



k) 



Longitudinal Stresses 

If because of wind loads or other factors 
the longitudinal stresses would be of im- 
portance, the least thicknesses in a length 
of arc in the most critical plane perpen- 
dicular to the axis of the pressure vessel 
may be averaged for computation of the 
longitudinal stresses. The thicknesses used 
for determining corrosion rates at the re- 
spective locations shall be the most critical 
value of average thickness. The potential for 
buckling shall also be considered. 

Local Metal Loss 

Corrosion pitting shall be evaluated in ac- 
cordance with 4.4.8.7. Widely scattered 
corrosion pits may be left in the pressure- 
retaining item in accordance with the fol- 
lowing requirements: 

1) Their depth is not more than one-half 
the required thickness of the pressure- 
retaining item wall (exclusive of corro- 
sion allowance); 

2) the total area of the pits does not exceed 
7 sq. in. (4500 sq mm) within any 50 
sq. inches (32000 sq mm); and 

3) the sum of their dimensions (depth and 
width) along any straight line within this 
area does not exceed 2 in. (50 mm). 

Weld Joint Efficiency Factor 
When the surface at a weld having a joint 
efficiency factor of other than one is cor- 
roded as well as surfaces remote from the 
weld, an independent calculation using 
the appropriate weld joint efficiency factor 
shall be made to determine if the thickness 
at the weld or remote from the weld governs 
the maximum allowable working pressure. 
For the purpose of this calculation, the 
surface at a weld includes 1 in. (25 mm) 
on either side of the weld, or two times the 
minimum thickness on either side of the 
weld, whichever is greater. 



I) Formed Heads 

1 ) When evaluating the remaining service 
life for ellipsoidal, hemispherical, tori- 
spherical or toriconical shaped heads, 
the minimum thickness may be calcu- 
lated by: 

a. Formulas used in original construc- 
tion, or 

b. Where the head contains more than 
one radii of curvature, the appro- 
priate strength formula for a given 
radius. 

2) When either integral or non-integral at- 
tachments exist in the area of a knuckle 
radius, the fatigue and strain effects that 
these attachments create shall also be 
considered. 

m) Adjustments in Corrosion Rate 

If, upon measuring the wall thickness at any 
inspection, it is found that an inaccurate 
rate of corrosion has been assumed, the 
corrosion rate to be used for determining 
the inspection frequency shall be adjusted 
to conform with the actual rate found. 

n) Riveted Construction 

For a pressure-retaining item with riveted 
joints, in which the strength of one or more 
of the joints is a governing factor in estab- 
lishing the maximum allowable working 
pressure, consideration shall be given as 
to whether and to what extent corrosion 
will change the possible modes of failure 
through such joints. Also, even though no 
additional thickness may have originally 
been provided for corrosion allowance 
at such joints, credit may be taken for the 
corrosion allowance inherent in the joint 
design. 



7B 



NATIONAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



4.4.7.3 ESTIMATING INSPECTION 
INTERVALS FOR PRESSURE- 
RETAINING ITEMS WHERE 
CORROSION IS NOT A FACTOR 

When the corrosion rate of a pressure-retaining 
item is not measurable, the item need not be 
inspected internally provided all of the follow- 
ing conditions are met and complete external 
inspections, including thickness measurements, 
are made periodically on the vessel. 

a) The non-corrosive character of the content, 
including the effect of trace elements, has 
been established by at least five years' 
comparable service experience with the 
fluid being handled. 

b) No questionable condition is disclosed by 
external inspection. 

c) The operating temperature of the pressure- 
retaining item does not exceed the lower 
limits for the creep range of the vessel 
metal. Refer to Table 4.4.8.1 . 

d) The pressure-retaining item is protected 
against inadvertent contamination. 



4.4.8 EVALUATING INSPECTION 

INTERVALS OF PRESSURE- 
RETAINING ITEMS EXPOSED TO 
INSERVICE FAILURE 
MECHANISMS 

Pressure-retaining items are subject to a variety 
of inservice failure mechanisms that are not 
associated with corrosion. The following pro- 
vides a summary of evaluation processes that 
may require a technical evaluation to assess 
resultant inspection intervals. 



4.4.8.1 EXPOSURE TO ELEVATED 
TEMPERATURE (CREEP) 

a) The owner-user of the pressure-retaining 
item and the Inspector are cautioned to 



seek competent technical advice to deter- 
mine which of the condition assessment 
methods can be used to ensure safe opera- 
tion and determination of the next inspec- 
tion interval for the pressure-retaining item 
when elevated service temperature is a 
consideration. 

b) When creep damage is suspected in a 
pressure-retaining item, an assessment of 
remaining service life should be determined 
either by the owner-user of the pressure-re- 
taining item or a competent engineer. This A07 
assessment may include, but is not limited 
to, the following methods: 

1 ) Dimensional measurements of the item 
to check for creep. 

2) Measurement of oxide scale and wall 
thickness for use in engineering analy- 
sis to determine remaining service life. 
Creep life can be predicted through an 
empirical approach that uses available 
data for the pressure-retaining compo- 
nent; total number of operating hours 
to the present is needed. Oxide scale 
thickness (steam side) can be measured 
directly from material samples or be 
measured in situ using ultrasonic tech- 
niques. 



TABLE 4.4.8.1 -Temperatures Above 
Which Creep Becomes a Consideration 



Carbon Steel and C-1/2 
Mo and Ferritic 
Stainless Steels 


750°F (400°C: 


tow Alloy Steels 
(Cr-Mo) 


850°F (455°C) 


Austenitic Stainless 
Steel 


950T(510°Q 


Aluminum Alloys 


200 r 'F (93 °C) 



3) Metal lographic examination to deter- 
mine the extent of exposure to creep 
damage. 



79 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



4) After removal of a material sample for 
creep rupture testing, a test matrix is 
selected to yield the most meaningful 
results from the sample. Test speci- 
mens are machined from the sample 
and tested under representative loads 
and temperatures (as selected in the 
test matrix). Creep strain vs. lime and 
temperature vs. time to rupture data are 
recorded. 



4.4.8.2 EXPOSURE TO BRITTLE 
FRACTURE 

a) Determining susceptibility to brittle fracture 
should be required as part of the overall as- 
sessment for evaluating remaining service 
life or to avoid failure of the pressure-retain- 
ing item during a pressure test. In order to 
carry out brittle fracture assessment, me- 
chanical design information, materials of 
construction and materials properties are to 
be determined. This information is required 
for pressure-retaining components in order 
to identify the most limiting component ma- 
terial that governs brittle fracture. Design in- 
formation, maintenance/operating history, 
and information relating to environmental 
exposure shall be evaluated to determine 
if there is a risk of brittle fracture. 

b) When brittle fracture is a concern, methods 
to prevent this failure shall be taken. These 
methods could include changes to oper- 
ating conditions and further engineering 
evaluations to be performed by a qualified 
engineer (metallurgical/corrosion/mechani- 
cal). Engineering evaluation methods to 
prevent brittle fracture shall be reviewed 
and accepted by the owner-user, Inspector, 

A07 and Jurisdiction, as required. 



4.4.8.3 EVALUATING CONDITIONS 

THAT CAUSE BULGES/BLISTERS/ 
LAMINATIONS 

a) Blistering in pressure-retaining items can 
result from laminations, inclusions in the 



metal, or damage mechanisms that oc- 
cur in service. Procedures for evaluating 
bulges/blistcrs/laminations are referenced 
in applicable standards (see 1 3). 

b) An engineering evaluation shall be per- 
formed to ensure continued safe operation 
when bulges/blisters/laminations are identi- 
fied. If a bulge/blister/lamination is within 
the specified corrosion allowance, further 
assessment shall be performed to evaluate 
any crack-like indications in surrounding 
base material. 

Note: Proximity of crack-like indications in 
welds and HAZ is important. Cracks and 
blisters should be evaluated separately. 



4.4.8.4 EVALUATING CRACK-LIKE 

INDICATIONS IN PRESSURE- 
RETAINING ITEMS 

a) Crack-like indications in pressure-retaining 
items are planar flaws characterized by 
length and depth with a sharp root radius. 
Cracks may occur within material or on the 
surface and may be individual or multiple 
in nature. In some cases, a conservative 
approach is to treat aligned porosity, inclu- 
sions, undercuts, and overlaps as crack-like 
indications. It is important that the cause 
of cracking is identified prior to any further 
determination of inspection intervals. 

b) If crack-like indications are on the surface 
and within the specified corrosion allow- 
ance, removal by blend grinding or air arc 
gouging can be performed. Measurements 
shall be taken to ensure minimum thickness 
is met and effective monitoring techniques 
should be established. If a crack-like flaw 
is not completely removed and repaired, 
then an engineering fracture mechanics 
or other evaluation must be performed to 
verify continued safe operation. 

c) There are various methods or approaches 
for evaluating crack-like indications, some 
of which are referenced in applicable stan- 
dards (see 1.3). 



BD 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



4.4.8.5 EVALUATING EXPOSURE OF A 

PRESSURE-RETAINING ITEM TO 
FIRE DAMAGE 

a) The extreme heat of a fire can produce 
visual structural damage and less apparent 
degradation of mechanical properties (de- 
crease in yield strength or fracture tough- 
ness). Potential damage includes changes in 
mechanical properties, decrease in corro- 
sion resistance, distortion, and cracking of 
pressure boundary components. Distortion 
of equipment extremities such as ladders 
and platforms does not necessarily mean 
that the pressure equipment is no longer 
suitable for continued service. Process 
fluid inside the vessel may serve as a cool- 
ing medium, thus preserving mechanical 
properties of the equipment. Instrumenta- 
tion and wiring are commonly damaged 
during a fire. Data requirements and history 
information should be obtained as identi- 
fied in 4.4.5. 

b) Recommended measurements and collec- 
tion of data for evaluation of fire damage 
shall include but are not limited to: 

1 ) Concentrated areas of fire damage ver- 
sus overall fire damage as it relates to 
normal operation 

2) Determination of cause and origin of 
fire 

3) Temperature extremes 

4) Nature of the fuel 

5) Source of ignition 

6) Time at temperature 

7) Cooling rate 

8) Photographs taken 



d) 



9) Plant personnel interviewed 

10) Actual strength and toughness proper- 
ties of the material 

Note: It is important that evidence be 
maintained in order to perform a proper 
evaluation. 

Components subjected to fire damage can 
exhibit altered mechanical properties, and 
should be evaluated to determine if the 
material has retained necessary strength 
and toughness as specified in the original 
code of construction. Heating above the 
lower critical temperature results in a phase 
transformation that upon rapid cooling can 
dramatically affect material properties. 
Evaluation methods may consist of: 

1) Portable hardness testing 

2) Field metallography or replication 

3) Pressure testing 

4) Magnetic particle testing 

5) Liquid penetrant testing 

6) Visual examination 

7) Dimensional verification checks 

If visual distortion or changes in the mi- 
crostructure or mechanical properties are 
noted, consider replacing the component 
or a detailed engineering analysis shall be 
performed to verify continued safe opera- 
tion. 

Techniques for evaluating fire damage are 
referenced in applicable standards. See 
1.3. 



s i 



NATIONAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



4.4.8.6 EVALUATING EXPOSURE OF 
PRESSURE-RETAINING ITEMS 
TO CYCLIC FATIGUE 

a) A fatigue evaluation should be performed 
if a component is subject to cyclic op- 
eration. The allowable number of cycles 
(mechanical or thermal) at a given level of 
stress should be adequate for the specified 
duration of service to determine suitability 
for continued operation. 

b) Data requirements and history information 
should be obtained as identified in 4.4.5. 

c) Techniques for evaluating fatigue are refer- 
enced in applicable standards. See 1 .3. 



4.4.8.7 EVALUATING PRESSURE- 
RETAINING ITEMS 
CONTAINING LOCAL THIN 
AREAS 

a) Local thin areas can result from corro- 
sion/erosion, mechanical damage, or 
blend/grind techniques during fabrication 
or repair, and may occur internally or exter- 
nally. Types of local thin areas are grooves, 
gouges, and pitting. When evaluating these 
types of flaws, the following should be 
considered: 

1) Original design and current operating 
conditions 

2) Component is not operating in the 
creep range 

3) Material has sufficient toughness 

4) Not operating in cyclic service 

5) Does not contain crack-like indica- 
tions 

6) Flaws are not located in knuckle regions 
of heads or conical transitions 



7) Applied loads 

8) The range of temperature or pressure 
fluctuation 

b) Where appropriate, crack-like indications 
should be removed by blend/grinding, and 
evaluated as a local thin area. 

c) Data requirements and history information 
should be obtained as identified in 4.4.5. 

d) Required measurements for evaluation of 
local thin areas shall include: 

1) Thickness profiles within the local 
region 

2) Flaw dimensions 

3) Flaw to major structural discontinuity 
spacing 

4) Vessel geometry 

5) Material properties 

e) Required measurements for evaluation of 
pitting corrosion shall include: 

1 ) Depth of the pit 

2) Diameter of the pit 

3) Shape of the pit 

4) Uniformity 

f) If metal loss is less than specified corrosion/ 
erosion allowance and adequate thickness 
is available for future corrosion, then moni- 
toring techniques should be established. If 
metal loss is greater than specified corro- 
sion/erosion allowance and repairs are not A07 
performed, a detailed engineering evalua- 
tion shall be performed to ensure continued 
safe operation. 



32 



NATIONAL BDARD INSPECTION CDDE • PART Z 



INSPECTION 



g) Techniques for evaluating local thin areas 
and pitting are referenced in applicable 
standards. See 1 .3. 



4.5.2 



DEFINITIONS 



A07 



A07 4.5 



A07 4.5.1 



RISK-BASED INSPECTION 
ASSESSMENT PROGRAMS 



SCOPE 



A07 a) This section describes the basic elements, 
principles, and guidelines of a risk based 
inspection (RBI) program. This section 
does not address any one method but is 
intended to clarify the elements associated 
with a RBI program. Risk assessment is a 
process to evaluate continued safe opera- 
tion of a pressure-containing component. 
This process is based on sound engineering 
practices, proven risk assessment experi- 
ence and management principles. There are 
numerous risk-based assessment methods 
being applied throughout many industries. 
Details for developing and implementing 
risk-based inspection programs are defined 
in other referenced standard. 

A07 b) Implementation of a risk-based inspection 
(RBI) assessment program allows an owner- 
user to plan inspection frequencies based 
on assessing probability of failure (POF) and 
consequence of failure (COF) (risk = POF x 
COF). Risk assessment programs involve a 
team concept based on knowledge, train- 
ing and experience between engineers, 
inspectors, operators, analysts, financial, 
maintenance, and management personnel. 
Appropriate and responsible decisions must 
be made from input by all team members to 
ensure safe operation of systems and their 
components. Organizational commitment 
and cooperation is required to successfully 
implement and maintain a RBI program. 



COF — Consequence of Failure. Outcome from A07 
a failure. There may be one or more outcomes 
from a single failure. 

POF — Probability of Failure. Extent to which A07 
a failure is likely to occur within a specific 
time frame. 

Risk — a combination of probability of an event A07 
occurring and the consequences associated 
with the event. Risk = (POF x COF). 

Risk Assessment — A process of risk analysis A07 
and evaluation. 

Risk Analysis — Identification and use of infor- A07 
mation such as historical data, opinions, and 
concerns to evaluate, treat, and accept risk. 

Risk-Based Inspection — Inspection managed A07 
through risk assessment. 

Risk Criteria — Terms used whereby the signifi- A07 
cance of risk is assessed, such as personnel safe- 
ty, cost benefits, legal/statutory requirements, 
economic/environmental aspects, stakeholders 
concerns, priorities, etc. 

Risk Evaluation — Process to compare risk with A07 
given criteria to determine the significance 
of risk to assist in accepting or mitigating the 
risk. 

Uncertainty — A measure of confidence in the A07 
expected value. 



4.5.3 



GENERAL 



A07 



Risk-based inspection assessment programs 
can provide the following benefits for organi- 
zations: 

a) An overall reduction in risk of equipment 
failure; 



B3 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 b) Identification of items not requiring inspec- 
tion or mitigation; 

A07 c) An acceptable understanding of the cur- 
rent risk for specific items under consider- 
ation; 

A07 d) Process safety improvements; by concen- 
trating inspections, maintenance and as- 
sociated expenditures on items of high risk 
and reducing efforts on low risk items; 

A07 e) Improved record retention for items by re- 
taining both historical and latest essential 
data and information needed for assess- 
ment; 

A07 f) Provides a management tool to continu- 
ally: 

1) maintain an effective inspection and 
maintenance program; 

2) improve reliability and safety for opera- 
tion; 

3) define staffing needs; 

4) evaluate and define funds required; 

5) adjusts risk assessment program based 
on desired results; and 

6) manage uncertainty. 



A07 4.5.4 CONSIDERATIONS 

Effective risk-based inspection programs should 
consider the following: 

a) Significance of failure on personnel safety; 

b) Identifying and obtaining accurate and 
appropriate information on system or com- 
ponent; 

c) Using appropriate inspection methods and 
types (internal, external, inservice, etc) fre- 
quencies, and understanding limitations; 



d) Design requirements; A07 

e) Installation requirements; 

f) Operational requirements and limitations; 

g) Proper execution of plans; 

h) Qualifications and training requirements A07 
for personnel; 

i) Use and development of procedures; 

j) Sound engineering and operating judg- 
ment; 

k) Effective communication among all affected 
areas of management and personnel; 

I) Jurisdictional and Inspector involvement as 
required; 

m) Human error; A07 

n) Consequential and secondary effects; and 

o) Impact of failure on personnel or opera- 
tions. 



4.5.5 KEY ELEMENTS OF AN RBI 

ASSESSMENT PROGRAM 



A07 



The following key elements should be included 
when establishing an RBI program: 

a) Establish objectives and goals; 

b) Understand risk of operation by identifying 
effects of inspection, maintenance, operat- 
ing parameters, and mitigating actions; 

c) Defining roles, responsibilities, training, 
and qualifications; 

d) Define risk criteria; 

e) Managed actions for acceptable levels of 
risk; 



84 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



A07 f) Understanding and meeting safety and 
environmental requirements; 

g) Optimizing expenditures; 

h) Assessing mitigation alternatives; 

i) Data and information collection; 

j) Identifying deterioration mechanisms (see 
Section 3 of this Part); 

k) Assessing POF and COF; 

I) Determine an acceptable risk matrix; 

m) Reassessing and updating RBI assessments; 
and 

n) Required documentation and retention. 



A07 4.5.6 



RBI ASSESSMENT 



Assessments provide a systematic approach to 
screen risk, identify areas of concern, and de- 
velop a list for needed inspections or analysis. 
Probability of failure (POF) and consequence of 
failure (COF) must first be evaluated separately. 
Risk is then determined as, (POF x COF) to de- 
velop a risk ranking measure or estimate. 



A07 4.5.6.1 



PROBABILITY OF FAILURE 



Probability of failure can be expressed in terms 
of number of events occurring during a specific 
time frame. There are three main considerations 
when analyzing POF. 

a) Evaluate deterioration mechanisms based 
on materials and the item's operating envi- 
ronment. 

b) Evaluate the impact of deterioration mecha- 
nisms on the integrity of the PRI(s). 

c) Determine the effectiveness of the inspec- 
tion program to quantify and monitor dete- 



rioration mechanisms either on or off-line, 
so that mitigation can be effective prior to 
failure. 



4.5.6.2 CONSEQUENCE OF FAILURE A07 

Consequence analysis involves logic modeling 
to depict combinations of events to represent 
effects of failure. These models usually contain 
one or more failure scenarios. Consequence 
categories for consideration include the fol- 
lowing: 

a) Personnel safety; 

b) Business/production effects including cost 
related to down time or collateral damage 
to surrounding equipment; 

c) Affected area; 

d) Environmental damage; 

e) Volume of fluid or gas released; 
Toxic or flammable events; and 

g) Maintenance/repairs/replacement. 



4.5.6.3 



RISK EVALUATION 



A07 



Once POF and COF are assessed and assigned, 
categories of risk can be calculated and evalu- 
ated. A risk matrix or plot is helpful to display 
or present risk without using numerical values 
with categories such as low, medium, and high 
typically assigned to identify POF and COF. 
POF and COF categories can be presented eas- 
ily to understand and manage risk. Using the 
risk evaluation, an inspection plan, including 
proposed inspection frequencies and appro- 
priate inspection methods is developed and 
implemented. 



85 



NATIONAL BOARD INSPECTION CODE ♦ PART 2 — INSPECTION 



A07 4.5.6.4 RISK MANAGEMENT 

Based on risk ranking and identifying accept- 
able thresholds, risk management or mitigation 
can proceed. When risk is considered unac- 
ceptable, the following action should be taken 
to minimize POP or COF. These may include 
but are not limited to the following: 

a) Decommissioning; 

b) Increased monitoring/inspection; 

c) Repair/Replace/maintain; 

d) De-rate equipment — needs/limits/cycles; 

e) Modifications/redesign; 

f) Training; and 

g) Enhance process control. 



A07 4.5.7 JURISDICTIONAL 

RELATIONSHIPS 

Jurisdictions mandate specific Codes/Standards 
with rules or laws that may differ between ju- 
risdictions. Frequency and types of inspections 
are examples of requirements that may vary. 
Owners and users implementing RBI assess- 
ment plans should understand jurisdictional 
requirements, so deviations from the mandated 
types of inspection and frequency of inspection 
can be requested. Methods used to develop and 
implement RBI assessment methods and the 
RBI program developed from those methods 
shall be acceptable to the jurisdiction and the 
inspector as required. 



as 




Fart 2, Section 5 
Inspection — Stamping, 
Documentation, and Forms 



87 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



PART 2, SECTION 5 

INSPECTION — STAMPING, 

DOCUMENTATION, AND FORMS 



5.1 



SCOPE 



This section provides guidelines and require- 
ments for stamping and documentation (Forms) 
for inservice inspections of PRIs. This section 
also describes evaluation of inspection results 
and assessment methodologies. 



5.2 



5.2.1 



REPLACEMENT OF STAMPING 
DURING INSERVICE 
INSPECTION 



AUTHORIZATION 



A07 



b) 



When the stamping on a pressure-retaining 
item becomes indistinct or the nameplate is 
lost, illegible, or detached, but traceability 
to the original pressure-retaining item is 
still possible, the Inspector shall instruct 
the owner or user to have the stamped data 
replaced. All re-stamping shall be done 
in accordance with the original code of 
construction, except as modified herein. 
Requests for permission to re-stamp or 
replace nameplates shall be made to the 
Jurisdiction in which the pressure-retaining 
item is installed. Application must be made 
on the Replacement of Stamped Data Form, 
NB-136 (see 5.3.2). Proof of the original 
stamping and other such data, as is avail- 
able, shall be furnished with the request. 
Permission from the Jurisdiction is not re- 
quired for the reattachment of nameplates 
that are partially attached. When traceabil- 
ity cannot be established, the Jurisdiction 
shall be contacted. 

When there is no Jurisdiction, the replace- 
ment of stamped data shall be authorized 
and witnessed by a National Board Com- 
missioned Inspector and the completed 
Form NB-136 (see 5.3.2) shall be submitted 
to the National Board. 



5.2.2 REPLACEMENT OF 

STAMPED DATA 

a) The re-stamping or replacement of data 
shall be witnessed by a National Board 
Commissioned Inspector and shall be iden- 
tical to the original stamping. 

b) The Re-stamping or replacement of a code 
symbol stamp shall be performed only as 
permitted by the governing code of con- 
struction. 

c) Replacement nameplates shall be clearly 
marked "replacement." 



5.2.3 



REPORTING 



Form NB-136 shall be filed with the Jurisdic- 
tion (if required) or the National Board by the 
owner or user together with a facsimile of the 
stamping or nameplate, as applied, and shall 
also bear the signature of the National Board 
Commissioned Inspector who witnessed the 
replacement. 



5.3 



5.3.1 



NATIONAL BOARD 
INSPECTION FORMS 



SCOPE 



The following forms may be used for document- A07 
ing specific requirements as indicated on the 
top of each form. 

Note: Jurisdictions may have adopted other 
forms for the same purpose and may not accept 
these forms. 



BB 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



5.3.3 



NEW BUSINESS OR DISCONTINUANCE OF BUSINESS FORM (NB-4) 



FORM NB-4 

NEW BUSINESS OR DISCONTINUANCE 

USED BY AUTHORIZED INSPECTION AGENCIES 



To:. 



JURISD CTION 



1. DATE OF SERVICE 



D New business 
2 Notice si: □ Discontinuance or cancellation 

G Refusa to inspect 



5 OBJECT 



6. OWNER'S NO 



10. NAME OF OWNER 



3 Ff ective date . 



□ High oressjre bo.ler 
4. Type oi object: D Low pressure boiler 

D Pressure vessel 



7. JURISDICTION NO. 



8. NATIONAL BOARD NO 



9. NAME OF MANUFACTURER 



11 . NAME OF OWNER INCLUDING COUNTY 



12. LOCATION OF OBJECT INCLUDING COUNTY 



13. USER OF OBJECT (IF SAME AS OWNER SHOW SAME") 



14, DATE OF LAST CERTIFICATE INSPECT, IF ANY 



■1 REMARKS (USE REVERSE SIDE) 



15. CERTIFICATE ISSUED 
DYes CNo 



16. REASON FOR DISCONTINUANCE OR CANCELLATION 

D Phys. condition DOUo'use D Other 



18. By:. 



INSPECTION AGENCY REP. 
This forr -nay be obtained frcn The National Beard of Boiler and Pressure Vessel Inspectors. 1055 Crupper Ave.. CcluTbis, OH 43229 



BRANCH OFFICE 
NB-i Rev. 2 



<3 1 



NATIONAL BOARD INSPECTION CODE ♦ PART Z — INSPECTION 



<32 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 5.3.7 REPORT OF FITNESS FOR SERVICE ASSESSMENT FORM (NB-403) 



The National Board of Boiler and Pressure Vessel Inspectors 

REPORT OF FITNESS FOR SERVICE ASSESSMENT 



F.F.S. Assessment No. 



1. Equipment Owner Information: ( J 



& 



(Name) 



(Address) 

2. FFS Assessment Performed \ 



By:®- 



(Name of Organization or Individual) 



(Address) 



3. Location of liquipment Installation: Lz j 

— (Name ol Companv 



& 



(Address) """* (Jurisdiction) 

4. Equipment or Component Infonnation: ( . ) 

^-^ (MFC. SR^, NBn. Jurisdiction?.' , Year Built, Other) 



(Hquipmenl Material Specilication. Grade) 



(Design & Operating Pressures, Design & Operating Tempera ;ures) 



5. Original Code of Construction: ( J 



(Name) (Section) (Division) (Edition) (Addendum) 



FITNESS FOR SERVICE STANDARD USED FOR ASSESSMENT ' 8 



6. Flaw Type(s) and/or Damage Mechanisms considered in FFS Assessment: ($) 



7. FFS Assessment Procedures (attach FFS Assessment reference documents with details if applicable): (10 J 



Inspection Results 



■®- 



(Type of'NDF. Performed, Pressure Tests, Thickness Measurements, etc.) 



Failure Modes Identified - ' '^ 



(Crack-Like Flaws, Pit.ing, Bulges/Blisters. General or Localized Corrosion, eit.) 



99 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 



8. FFS Assessments Results / Recommendations (Check boxes that apply and provide details): 

Continue Operation Until: _ 



(ViXJ Continued Operation f^Q Repair ^16^ Replace (wXl 



Details (if applicable) 



9. Owners Inspection Intervals (Based on Assessment): ( ) 

10. Inservice Monitoring Methods and Intervals: [~ J 

11. Operating Limitations (if applicable): \~ J 



(MonthsA'ears) 



(Methods, Months-Years) 



. certify that to the best of my knowledge and belief 



I, 

the statements inlRis report are correct and that the information, data, and identification numbers are 
correct and in accordance with provisions of the National Board Inspection Code, Pail 2, 4.4. Applicable 
documentation is attached to support this assessment. 



Owner Name . 



Signature . 



(Printed} 



__ Date . 



(Owner) 



Organization Performing Assessment [~ J 



(Namci 



Signature . 



Date. 



(Responsible Engineer) 



Verified By . 



(Inspector. Printed) 



Employer ( ) 

^ 1 Ac, 



Signature . 



(Accredited Inspection Agency) 

Date. ' 32 



(Inspecior) 



NB Commission # 



(National Board &. 
Jurisdiction Number) 



Th;s tern m=>v be ojla n?c t-pr- 1 ~e Na: era 3c a f d cf 3o ler and Pressj-e \"esscl r-:p?oi;,. 1C55 Ciuxsr Ay.?.. Col.jmci.s, OH 4322-j 



1 OD 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07 5.3.7.1 GUIDE FOR COMPLETING 
FITNESS FOR SERVICE 
ASSESSMENT REPORTS 

1. For tracking and reference purposes indi- 
cate the sequential Fitness for Service 
Assessment number. 



1 1 . Description of the Inspection and NDE re- 
sults as prescribed in the Fitness for Service 
Assessment analysis. 

12. Description of the Failure, Damage and/or 
Deterioration modes identified in the Fit- 
ness for Service Assessment. 



2. Name and address of the owner of the 
equipment that is being assessed for Fitness 
for Service. 



13. Indicate the results of the Fitness for Service 
Assessment, including remediation recom- 
mendations. 



3. Name and address of the organization or 
individual performing the Fitness for Ser- 
vice Assessment. 

4. Name and address of the facility where the 
equipment being assessed for Fitness for 
Service is located. 

5. Name of the Jurisdiction where the assessed 
equipment is located. 

6. Identification of Equipment including 
Manufacturer, Manufacturer's serial num- 
ber, National Board Number, Jurisdiction 
assigned registration number, and Year 
built. Also include Equipment/Component 
Material Specification/Grade, Design and 
Operating Pressures, Design and Operating 
Temperatures, if applicable. 

7. Indicate the name, section, division, edi- 
tion, and addenda of the original Code of 
Construction. 

8. Name of the Standard used to perform the 
Fitness for Service Assessment. 

9. Description of the Equipment/Component 
damage mechanism or flaw types consid- 
ered in the Fitness for Service Assessment. 

10. Description of the Fitness for Service As- 
sessment level and technique. Attach all 
relevant Fitness for Service Assessment 
procedures and detailed documentation. 



14. Indicate if the equipment can continue 
current operation. 

15. Indicate if repairs are required. 

16. Indicate if equipment replacement is re- 
quired. 

1 7. Indicate if continued operation has a finite 
date. 

1 8. Indicate finite date of continued operation 
(if applicable). 

19. Indicate the required Inspection intervals 
as determined by the Fitness for Service 
Assessment. 

20. Indicate the required inservicc monitoring 
methods and intervals for the equipment as 
defined by the Fitness for Service Assess- 
ment. 

2 1 . Describe any operating or inservice limita- 
tions for the equipment. This would include 
any reductions /changes in operating pres- 
sures or temperatures. 

22. Type or print the name of the representative 
of the Organization or individual perform- 
ing the Fitness for Service Assessment. 

23. Name of the Owner of the equipment. 

24. Signature of Owner. 



1 D 1 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 25. Indicate the month, day, and year of the 
Owner review and acceptance of Fitness 
for Service Assessment. 

26. Indicate the name of the organization per- 
forming the Fitness for Service Assessment 
(this may be the same name as in line 22) 

27. Signature of the responsible engineer 
performing the Fitness for Service Assess- 
ment. 

28. Indicate the month, day, and year of the 
completion of the Fitness for Service Assess- 
ment by the Organization responsible. 

" 29. Type or print the name of the Inspector. 

30. Name of the Accredited Inspection Agency 
employing the Inspector. 

31 . Signature of the Inspector. 

32. Indicate the month, day, and year of the 
review and acceptance by the Inspector of 
the Fitness for Service Assessment. 

33. National Board commission number of 
Inspector, Jurisdiction, and Certificate of 
Competency Numbers. 



1 D2 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 

plugs and placing a fan or air blower on 
top of the steam dome opening to force air 
into the boiler. For the firebox this can be 
accomplished by opening the smokebox 
door and firebox door and placing a fan 
or air blower at either location to force air 
through. Failure to do this could result in 
asphyxiation of the personnel entering the 
boiler or firebox. 

b) If possible, the locomotive should be moved 
into a heated engine house and the boiler 
allowed to warm up in the air for several 
days until it is the same temperature as the 
air. 

c) The initial fire up should be done slowly to 
allow even heating of the boiler. 

d) Before movement, the cylinders should be 
warmed up by allowing a small quantity 
of steam to blow through them and out the 
cylinder cocks and exhaust passages. This is 
necessary to reduce the stress in the casting 
from thermal expansion of the metal. 

e) Steam should be discharged through the 
cylinder cocks for several minutes to aid 
removal of any solvent, debris, or rust that 
may have formed in the superheater units, 
steam pipes, and dry pipe. 

f) All appliances should be tested under steam 
pressure before the locomotive is moved. 



1 23 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



SUPPLEMENT 2 

HISTORICAL BOILERS 



S2.1 



SCOPE 



a) This supplement is provided as a guide to 
inspection of historical steam boilers of 
riveted and/or welded construction not fall- 
ing under the scope of Supplement 1 . These 
historical steam boilers would include: 
steam tractors, traction engines, hobby 
steam boilers, portable steam boilers, and 
other such boilers that are being preserved, 
restored, and maintained for demonstra- 
tion, viewing, or educational purposes. 

A07 Note: This supplement is not to be used 
for steam locomotive boilers falling under 
the requirements of the Federal Railroad 
Administration (FRA). FRA rules for steam 
locomotive boilers are published in 49 CFR 
230. Specific rules and special require- 
ments for inspection, repairs, alterations, 
and storage of steam locomotive boilers are 
identified in Supplement 1 of the NBIC. 

b) The rules specified in this supplement shall 
be used in conjunction with the applicable 
rules in this Code. References specified or 
contained in this Supplement may provide 
additional information to assist the user 
when applying the requirements of this 
supplement. 



S2.2 



INTRODUCTION 



A07 a) The following inspection rules are mini- 
mum requirements for safe and satisfactory 
operation of historical boilers. Users of 
this supplement are cautioned that where 
complete details are not provided, the user 
is advised to seek technical guidance to 
provide good sound engineering evalua- 
tions and practices. 

A07 b) Where adopted by a Jurisdiction, these 
requirements are mandatory. Where a Ju- 



risdiction establishes different requirements 
for historical boilers or where a conflict 
exists, the rules of the Jurisdiction prevail. 



S2.3 



RESPONSIBILITIES 



The owner-user and/or operator are responsible 
for ensuring that the boiler meets the require- 
ments of the Jurisdiction where the boiler 
is operated, including inspections, repairs, 
licensing, operating certificates, permits, and 
operator training. 

Note: It should be recognized that safety of 
these boilers is dependent upon the knowledge 
and training of the operator in proper use, re- 
pair, maintenance, and safe operation of each 
specific boiler proposed to be operated. (See 
S2.4.3) 



S2.4 GENERAL INSPECTION 

REQUIREMENTS 

The owner-user and Inspector should refer to 
1 .4 Personnel Safety, Section 3 of this Part, Cor- 
rosion and Failure Mechanisms, and Section 4 
of this' Part, Examinations, Test Methods, and 
Evaluations, for additional information when 
performing inspections. 



S2.4.1 PRE-INSPECTION 

REQUIREMENTS 

a) The owner or user has the responsibility to 
prepare the boiler for any required inspec- 
tions needed to ensure safety as deemed 
necessary by the Inspector. Prior to perform- 
ing any type of inspection, the owner and 
Inspector shall ensure safety precautions 
are taken to prevent personal injury. 

b) Prior to conducting an inspection, the fol- 
lowing shall be reviewed by the Inspector 
to the extent possible to aid in determining 
safe operation: 



1 24 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



1) Operating and maintenance history 
and/or other information contained in 
the Operator Log Book; 

2) Inspection history; 

3) Construction Code/Design; 

4) Materials — types and thickness; 

5) Certifications; 

6) Operator knowledge and training as 
required by the Jurisdiction; 

7) Repairs/Alterations performed; 

8) Cleanliness of the boiler; and 

9) Potential hazards to personnel. 

Note: If a boiler has not been properly 
prepared for an inspection, the Inspec- 
tor may decline to make the inspec- 
tion. 

S2.4.2 POST-INSPECTION ACTIVITIES 

a) Upon completion of inspection activities, 
the results of examinations and tests shall 
be documented by an Inspector, in a man- 
ner acceptable to the Jurisdiction. 

b) Any defects or deficiencies in the condition, 
operation, and/or maintenance practice 
of the boiler and appurtenances shall be 
discussed and documented with the owner 
and/or user. Recommendations for correc- 
tion and/or repair requirements (if required) 
shall be discussed and documented. 



A07 S2.4.3 



BOILER OPERATORS 



inspection and testing for each boiler pro- 
posed to be operated: 

1) Jurisdictional rules for construction, A07 
maintenance, repairs, operation, and 
certification. 

2) Boiler functions and purpose of con- 
trols, appurtenances, and safety de- 
vices. 

3) Proper operation, maintenance, types, 
use and testing of valves including 
safety valves. 

4) Fusible plugs including installation, 
maintenance, design, and purpose. 

5) Performance of normal and emergency 
system operating procedures associated 
with blowdown of the boiler, feed, or 
water delivery system, steam system, 
water level control, and combustion of 
fuel. 

6) Importance of maintenance, cleaning, 
and inspection of components and 
safety devices such as pressure gages, 
sight glass, governor, water column, 
firebox, etc. 

7) Preparation and actions to be taken on 
emergency situations for fire, low water, 
foaming, overpressure, and excessive 
leakage. 

b) Organizations/associations involved with 
historical boilers should verify operator 
knowledge by examination or practical 
testing or a combination of both. Some 
Jurisdictions may require specific operator 
qualifications or certifications. (See addi- 
tional safety procedures in S2.14). 



a) The following guidelines should be under- 
stood by each historical boiler operator and 
demonstrated safely during jurisdictional 



1 25 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



S2.4.4 



EXAMINATIONS AND TESTS 



The examinations and tests shall be as re- 
quired by the Jurisdiction and verified by an 
Inspector. The Inspector shall accept and verify 
procedures and personnel qualifications when 
examinations and tests are performed. 



S2.4.4.1 NONDESTRUCTIVE 

EXAMINATION METHODS 

There are a variety of nondestructive examina- 
tion methods that may be employed to assess 
the condition of historical boilers. Skill, expe- 
rience, and integrity of personnel performing 
examinations are essential to obtaining mean- 
ingful results. Generally, some form of surface 
preparation will be required prior to the use of 
examination methods. 



S2.4.4.2 TESTING METHODS 

Testing should be performed by experienced 
personnel using procedures acceptable to the 
Inspector. Typical test methods available to the 
Inspector during the inspection of historical 
boilers are listed below: 

a) Hydrostatic testing/pressure testing; 

b) Leak testing; and 

c) Ultrasonic thickness testing. 



S2.5 SPECIFIC EXAMINATION AND 

TEST METHODS 



S2.5.1 SPECIFIC EXAMINATION 

METHODS 

A07 a) This part describes nondestructive exami- 
nation and test methods that are typically 
available to the Inspector during inspection 
of historical boilers. 

1) Visual (VT) 



b) 



2) Ultrasonic (UT) 

3) Liquid Penetrant (PT) 

4) Magnetic Particle (MT) 

5) Radiographic (RT) 

Additional examination or test methods A07 
may be performed if a deficiency is de- 
tected during initial or reoccurring inspec- 
tion. Use of additional examination and 
testing methods shall be acceptable; to the 
Inspector and the Jurisdiction, if required. 



S2.5.2 



VISUAL EXAMINATION 



Visual examination is the most widely used 
method to ascertain surface condition and 
recognize surface features typical of various 
damage mechanisms associated with historical 
boilers. Damage mechanisms such as corrosion 
or cracking may be due to operation, age of 
material, or improper maintenance. 



S2.5.2.1 PREPARATION FOR VISUAL 

INSPECTION 

The owner-user shall ensure the following areas 
as a minimum are prepared for visual examina- 
tion, and is acceptable to the Inspector at the 
time of the examination. 

a) Fireside open and grates removed 

b) Fireside tubesheets and tubes thoroughly 
cleaned of soot and ash 

c) Waterside drained and hand holes, plugs, 
and inspection openings removed 

d) Sediment, scale, and mud flushed 

e) Insulation or jackets removed as appropriate A07 

Note: Where there is limited or no access 
for visual inspection, remote camera or 
fiber optic devices may be used. 



1 26 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



A07 S2.5.2.2 



VISUAL EXAMINATION 
REQUIREMENTS 



To the extent possible, the following areas 
and items shall be visually examined by the 
Inspector and results documented on the boiler 
inspection guideline (S2.1l) provided in this 
supplement, or as required by the Jurisdiction. 
Use of the boiler inspection guideline should 
be used as a reference when performing visual 
inspections. 

a) The fusible plugs shall be removed, inspect- 
ed, and confirmed to meet requirements of 
S2.8.4. 

A07 b) Threaded openings or connections in the 
boiler shall be inspected for wear or dete- 
rioration when there is evidence of leakage. 
ANSI standard plug and ring gages may be 
used to verify thread integrity. 

c) Inspect the condition of boiler sheets, shell, 
tubesheets, fittings, staybolts, and other 
materials for thinning, pitting, cracks, or 
corrosion. 



S2.5.5 MAGNETIC PARTICLE 

EXAMINATION 

Magnetic particle examination can be used to 
reveal surface discontinuities and to a limited 
degree discontinuities slightly below the sur- 
face. The sensitivity of this method decreases 
rapidly with depth below the surface and 
therefore is used primarily to examine surface 
discontinuities. 



S2.6 



SPECIFIC TESTING METHODS 



During inspection of historical boilers there 
may be instances where conditions have ad- 
versely affected the tightness of the boiler or 
the inspection discloses hard to evaluate forms 
of deterioration that may affect the safety of 
the vessel. In these specific instances, a pres- 
sure test using water or other suitable liquid 
test medium may be required at the discretion 
of the Inspector to assess leak tightness of the A07 
pressure-retaining item. For safety, pneumatic 
pressure tests shall not be performed. 



d) Verify that requirements of S2.8 through 
S2.9 are in compliance, as applicable. 



S2.5.3 



ULTRASONIC EXAMINATION 



Ultrasonic examination is used as a volumet- 
ric examination of welds and base materials 
for detection of flaws. Factors such as mate- 
rial composition, surface condition, choice of 
equipment, and ability of the operator affect 
the results of ultrasonic examination. 



S2.5.4 LIQUID PENETRANT 

EXAMINATION 

Liquid penetrant examination is used to detect 
discontinuities open to the surface such as 
cracks, seams, laps, cold shuts, laminations, 
and porosity. 



S2.6.1 HYDROSTATIC PRESSURE 

TESTING 

When performing hydrostatic pressure test- 
ing for verification of leak tightness or when 
required by the Jurisdiction, the following 
requirements shall be met: 

a) Hydrostatic pressure test shall be between 
the calculated maximum allowable work- 
ing pressure and 1 .25 times the calculated 
maximum allowable working pressure, A07 
and held for a minimum of 10 minutes or 

as required to perform a complete visual 
examination. 

b) The metal and water temperature of the 
boiler shall be between 60°F to 1 20 C F (1 6°C 
to 49°C) anytime a hydrostatic test is being 
performed. 



1 27 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



c) A calibrated gage acceptable to the Inspec- 
tor shall be used when hydrostatically pres- 
sure testing a boiler. 

d) During hydrostatic testing, safety valve(s) 
shall be removed. 



S2.6.2 ULTRASONIC THICKNESS 

TESTING 

Ultrasonic thickness (UT) testing shall be per- 
formed to determine boiler plate thickness. 
UT testing shall be performed by personnel, 
acceptable to the Jurisdiction and the Inspector. 
The following requirements shall be met to the 
extent possible. Performance and results shall 
be acceptable to the Inspector and, if required, 
the Jurisdiction. 

a) Equipment, operator, and calibration stan- 
dards used shall be documented. 

A07 b) To calculate MAWP, ultrasonic thickness 
testing results in areas of generalized thin- 
ning (3 in. [76 mm] in diameter or greater) 
or where grooved thinning is noted (2 in. 
[50 mmj in length or greater) are to be used 
in determining minimum thickness in ac- 
cordance with S2.1 0. The MAWP calcula- 
tion in S2.1 shall be completed based on 
the thickness data gathered. 

A07 c) On initial UT of stayed sections, the plate 
thickness readings should be taken on a grid 
not exceeding the maximum staybolt pitch. 
Additional readings may be taken close 
to each staybolt to determine if localized 
thinning has occurred. Particular attention 
should be given to the joint between the 
staybolt and the plate. 

d) On initial UTof unstayed sections, the plate 
thickness readings should be taken on a 
grid not exceeding 12 inch (300mm) cen- 
ters. Additional readings should be taken if 
conditions warrant. 

e) UT test results shall be documented so 
location of test results can be checked at 



subsequent UT tests to determine if material 
loss has occurred. 

Recurring UT testing shall be performed 
by randomly checking 10% of original UT 
checks. Areas of thinning identified during A07 
previous inspections shall be given particu- 
lar attention. If material loss is determined, 
additional testing may be requested by the 
Inspector. 

The owner/operator shall maintain the A07 
initial and recurring grid mapped UT read- 
ings in conjunction with the calculations in 
permanent boiler records. Documentation 
shall be available to the Inspector for review 
and acceptance. 



S2.7 



INSPECTIONS 



The requirements of this section shall be used 
in conjunction with the general requirements 
identified in S2.4. 



S2.7.1 



INSERVICE INSPECTIONS 



The following examinations and tests shall be 
performed while the boiler is in operation: 

a) Two independent means of boiler feed 
water delivery systems shall be demon- 
strated to the Inspector. Observance to be 
performed at an operating pressure no less 
than 90% of the safety valve set point of the 
boiler. If the boiler is equipped with more 
than one feedwater tank, each feedwater 
device must be able to take water out of 
either feedwater tank. Pumped feedwater A07 
shall be preheated prior to entering the 
boiler. 

b) Demonstration of operable try cocks that 
show a level of water that correlates with 
that shown in the gage glass. 

c) Demonstration of operating gage glass up- 
per and lower shutoff valves. 



1 28 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



d) Demonstration of an operating gage glass 
blovvdown valve. 



2) A visual inservice examination per A07 
S2.7.1; 



e) Check that the gage glass is visually clear 
and fully operational. 

f) Visual inspection for leaks. 

g) Safety valves shall be tested by having the 
operator raise boiler pressure to the safety 
valve popping point. Popping point pres- 
sure and blovvdown will be observed to 
ensurethey are within tolerances (see S2.8). 
Alternatively, a certification acceptable to 
the Jurisdiction maybe used for verification 
of set pressures. 



A07 S2.7.2 INSERVICE INSPECTION 

DOCUMENTATION 

Inservice inspection shall be documented as 
required by the Jurisdiction where the boiler 
is operated, or Form NB-5 or similar form may 
be used. 



S2.7.3 



INSPECTION INTERVALS 



3) Initial UT test requirements per 
S2.6.2; 

4) MAWP calculation per S2. 10; 

5) Hydrostatic Pressure Testing per S2. 6.1; 
and 

6) Other examinations (UT, PT, MT) as 
required by the Jurisdiction or Inspector 
to determine boiler integrity. 



S2.7.3.2 SUBSEQUENT INSPECTIONS A07 

a) Boilers that have completed the initial 
inspection requirements begin the subse- 
quent inspection intervals. The following 
inspection intervals should be used unless 
other requirements are mandated by the 
Jurisdiction. 

1) Interval 9} — one year following initial 
inspection. Inservice inspection per 

S2.7.1. 



S2.7.3.1 INITIAL INSPECTION 

A07 a) Initial inspections shall be performed to 
determine baseline criteria needed for the 
operating life of the boiler. The owner-user 
shall maintain documentation and inspec- 
tion results as required by this section. In 
addition to the required Jurisdiction inser- 
vice inspection report identified in S2.7.2, 
Form CM (See S2.12) may be used for the 
documentation of initial examinations and 
inspections. 

b) Boilers initially evaluated in accordance 
with this inspection code shall be subject 
to the following examinations and tests: 

1) A visual internal examination per 
S2.5.2; 



2) Interval #2 — two years following ini- 
tial inspection. Visual inspection per 
S2. 5.2.2. 

3) Interval #3 — three years following 
initial inspection. A pressure test per 
S2.6.1. 

4) Interval #4 — same as interval #1 . 

5) Interval #5 — Visual inspection per 
S2.5.2.2 and UT thickness testing per 
S2.6.2. 

6) Interval #6 same as interval #3. 

b) After interval #6 is completed, the sub- 
sequent inspection cycle continues with 
interval #1 . 



1 29 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



S2.8 SAFETY DEVICES — GENERAL 

REQUIREMENTS 

Each boiler shall be equipped wilh the follow- 
ing safety devices: safety valve(s), gage glass(s), 
try-cock(s), fusible plug(s), and pressure gage(s). 
These safety devices shall be verified by the 
owner and inspector and documented on the 
Boiler Inspection Guide S2.1 1 for proper instal- 
lation and purpose during each inspection. 



ity should be avoided. (Only heating 
surface area above the grates shall be 
used when calculating heating surface 
for safety valve required capacity.) 

Note: An additional pressure relief A07 
valve may be used in conjunction with 
the above required ASME safety valve 
if set at a lower pressure, although no 
credit for relieving capacity may be 
used. 



S2.8.1 



SAFETY VALVES 



A07 a) The following requirements shall be verified 
acceptable when performing inspections of 
safety valves. 

A07 1) Set pressures of safety valves installed 
shall be verified by operation or certi- 
fication acceptable to the jurisdiction. 

2) Safety valve(s) shall be National Board 
capacity certified. 

3) Safety valve(s) shall be sealed by an 
ASME "V" Stamp holder or NIB "VR" 
repair firm. 

A07 4) The required safety valve capacity in 
pounds per hour (kg per hour) shall 
be calculated by multiplying boiler 
heating surface area by the type of fuel 
factor used (see Table S2.8.1 for fuel 
factors). Excessive safety valve capac- 



5) Safety valve(s) shall have a test lever. 

6) No isolation valve of any description 
shall be placed between the required 
safety valve(s) and the boiler, or on the 
discharge pipe between the valve and 
the atmosphere. 

7) The piping connection between the 
boiler and the safety valve shall not 
be less than the inlet size of the safety 
valve, and the discharge pipe, if used, 
shall not be reduced between the safety 
valve and the point of discharge. 

b) To reduce cycling stress on the boiler, it is A07 
recommended that a safety valve with a 
blowdown between 2% and 4% is used. 
The blowdown, however, should never 
exceed 6%. 



TABLE S2.8.1 

Minimum Pounds of Steam per Hour per Square Foot of 

Heating Surface (1 lb. Steam/hr./sq. ft. [4.88 kg/hr./sq. m]) 


Boiler Heating Surface 


Fireiube Boilers 


Watertube Boilers 


Hand-Fired 


5 


6 


Stoker-Fired 


7 


8 


Power Burner 


8 


10 


Hand-Fired Watervvall 


8 


8 


Stoker Waterwal I 


10 


12 


Power Burner Watervvall 


14 


16 





1 3D 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



S2.8.2 



CAGE GLASS 



Historical boilers shall be equipped with at 
least one gage glass meeting the following 
requirements: 

a) The gage glass shall be fitted with a guard 
to protect the glass. 

b) The gage glass shall indicate the minimum 
safe operating water level. 

c) The gage glass shall be provided with a drain 
valve or petcock, piped to a safe location. 

A07 d) The gage glass shall be visually clear and 
fully operational. 

A07 c) The distance from the highest point on the 
crown sheet to the top of the lowest pack- 
ing nut of the gage glass should be checked 
and documented. 



S2.8.3 



TRY-COCKS 



Historical boilers shall be equipped with try 
cocks meeting the following requirements: 

a) Try cocks shall be correctly located in 
reference to the minimum required water 
level. 

b) Try cocks shall be open (unplugged) and 
fully operational. 

c) If the boiler was not originally fitted with try 
cocks, a newly installed try cock shall be 
located 3 inches above the crownsheet. 



b) Boilers shall have a fusible plug unless 
equipped and operated with automatic 
controls. 

c) Fusible plugs shall be constructed to meet 
the requirements of the ASME Code, and 
indicated as such by the ASME marking on 
the filler material. 

d) Fireside fusible plugs must protrude a mini- 
mum of 3/4 inch (19 mm) into the water. 

e) Fusible plugs may not protrude into the fire 
area more than 1 inch (25 mm). 

f) Fusible plugs shall not be refilled. 

g) Fusible plugs shall be replaced on initial A07 
jurisdictional inspection and after 500 
hours of service, if hour of service can be 
proven. If hours of service cannot be proven 
they shall be replaced every three calendar 
years. Fusible plug life shall not exceed ten 
calendar years. 

h) Leaking fusible plugs shall be replaced. A07 



S2.8.5 



PRESSURE GAGE 



S2.8.4 



FUSIBLE PLUG 



Historical boilers shall be equipped with at 
least one pressure gage meeting the following 
requirements: 

a) Tested and proven accurate; within plus or 
minus 5 psi (35 kPa) of the safety valve set 
point at the time of the inservice inspection 
pressure test. If the gage is found to be out 
of this specified range it shall be calibrated 
to a national standard using a master gage A07 
or dead weight tester traceable to a national 
standard. 



Historical boilers equipped with fusible plugs 
shall meet the following requirements: 

A07 a) The fusible plug shall be inspected to de- 
termine the condition of the threads in the 
crown sheet and on the fusible plug. 



b) Siphon, or water seal, shall be installed 
between pressure gage and boiler. 

c) If a valve is installed between the gage and 
the boiler, the valve shall indicate the open 
position or be sealed open. 



1 3 i 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07 d) The range of pressure gage shall be 1 .5 to 
3.5 times the set point of the safety valve. 



S2.9 APPURTENANCES — PIPING, 

FITTINGS, AND VALVES 

Boiler piping and fittings shall meet the follow- 
ing requirements: 

a) Threaded openings shall follow accepted 
standard piping practices and ANSI general 
pipe thread requirements. 

b) Schedule 80, black pipe (SA-53 GR. A or B 
types ERW or Seamless; SA-1 06 GR.A,B,C) 
shall be used for boiler pressure piping. 
Galvanized pipe and fittings and A-53 Type 

A07 H and API-5L Grade A 25 pipe are prohib- 
ited on boiler pressure piping. 

c) Steam piping components shall be used in 
the manner for which they were designed 
and shall not exceed manufacturer's pres- 

A07 sure rating. Malleable iron Class 300 
threaded fittings per ASME B16.3 are ac- 
ceptable for use. The use of malleable iron 
class 150 is not recommended. Forged 
threaded fittings per ASME B16.1 1 classes 
2000-6000 are acceptable for use. 

d) The blowdown line shall be piped to a safe 
point of discharge during the time the boiler 
is operating. 

e) Piping shall be properly supported. 

A07 f) Valves shall be used in the manner for 
which they were designed, and shall be 
used within the specified pressure-tem- 
perature ratings. Valves shall be rated at 
or above the pressure setting of the boiler 
safety valve, denoted by the general or 
primary pressure class identification on the 
valve body and/or by the initials "WSP" or 
"S" to indicate working steam pressure or 



steam rating. Valves in cold water service 
may be designated by the initials "WOG" 
to indicate water, oil, or gas rating and/or 
by the pressure class identification on the 
valve body. 

The boiler shall be equipped with two 
means of supplying feedwater while the 
boiler is under pressure. 



S2.9.1 PIPING, FITTINGS, AND VALVE 

REPLACEMENTS 

The installation date should be stamped or 
stenciled on the replaced boiler piping. Alterna- 
tively, the installation date may be documented A07 
in permanent boiler records, such as the opera- 
tor log book. 



S2.10 MAXIMUM ALLOWABLE 

WORKING PRESSURE (MAWP) 

Note: The rules of ASME Section I 1971 Edi- 
tion, Part "PR" and "PFT" may be used for 
determining specific requirements of design 
and construction of boilers and parts fabricated 
by riveting. 1 ' 

The MAWP of a boiler shall be determined by 
computing the strength of each boiler compo- 
nent. The computed strength of the weakest 
component using the factor of safety allowed 
by these rules shall determine the MAWP. 



S2.10.1 STRENGTH 

a) In calculating the MAWP, when the ten- 
sile strength of the steel or wrought iron 
is known, that value shall be used. When 
the tensile strength of the steel or wrought 
iron is not known, the values to be used A07 
are 55,000 psi (379 MPa) for steel and 
45,000 psi (310 MPa) for wrought iron. 



2 Copies of ASME Section I 1971 Edition Part "PR" and 
"PFT" referenced section may be obtained by contacting the 
National Board of Boiler and Pressure Vessels, 1055 Crupper 
Ave., Columbus, Ol I 4.S229. 



1 32 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Original steel stamp marks, original mate- 
rial certifications, or current laboratory tests 
are acceptable sources for verification of 
tensile strength. Catalogs and advertising 
literature are not acceptable sources for 
tensile strength values. 

b) In computing the ultimate strength of riv- 
ets in shc^ar, the following values shall be 
used: 

1 ) Iron rivets in single shear 
38,000 psi (262 MPa) 

2) Iron rivets in double shear 
76,000 psi (524 MPa) 

3) Steel rivets in single shear 
44,000 psi (303 MPa) 

4) Steel rivets in double shear 
88,000 psi (607 MPa) 

A07 c) The resistance to crushing of mild steel shall 
be taken as 95,000 psi (655 MPa) unless 
otherwise known. 

A07 d) S = TS/FS. See definitions of nomenclature 
in S2.10.6. 



S2.10.2 RIVETS 

When the diameter of the rivet holes in the 
longitudinal joints of a boiler is not known, 
the diameter of rivets, after driving, may be 
ascertained from the Table S2.10.2. 



strength of the plate, the efficiency of the lon- 
gitudinal joint, the inside diameter of weakest 
course, and the design margin allowed by 
these rules using the following formula orTables 
S2. 10.3.1 through S2. 10.3.6: 



MAWP = 



TS x t x E 
(R x FS) 



See definitions of nomenclature in S2. 1 0.6. 



TABLE S2.1 0.2 

Sizes for Rivets Based on 

Plate Thickness 


Thickness of 
Place, inches 
(mm) 


Diameter of 
Rivet after Driving, 
inches (mm) 


1/4(6) 


11/16(17) 


9/32 (7) 


11/16(17) 


5/1 6 (8) 


3/4(191 


1 1/32 (9) 


3/4(19) 


3/8(10) 


13/16(215 


13/32 (10) 


13/16(21) 


7/16(11) 


15/16(24) 


15/32(12) 


13/16(24) 


1/2(13) 


1 5/1 6 (24) 


9/1 6 (1 45 


1-1/16(27) 


5/8(16) 


1-1/16(27) 





S2.10.3 CYLINDRICAL COMPONENTS 

The MAWP of cylindrical components under 
internal pressure shall be determined by the 
strength of weakest course computed from the 
minimum thickness of the plate, the tensile 



1 33 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



TABLE S2.1 0.3.1 

Maximum Allowable Working Pressure for Cylindrical 

Components (Barrel) 

For Single Riveted Lap Joint 






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1 34 



NATIONAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



TABLE S2.1 0.3.6 

Maximum Allowable Working Pressure for 

Cylindrical Components (Barrel) 

For Buttstrap Quadruple Riveted Joint 




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1 39 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



S2.10.4 STAYED SURFACES 

The maximum allowable working pressure for 
stayed flat plates and those parts which, by 
these rules, require staying as flat plates with 
stays or staybolts of uniform diameter sym- 
metrically spaced, shall be calculated using 
the following formula or Tables S2.10.4 and 
S2. 10.4.1: 



A07 P 



TxSxC 



See definitions of nomenclature in S2.1 0.6 



A08S2.10.4.1 STAYBOLTS 

Table S2. 10.4.1 may be used to determine 
the MAWP for corroded staybolts. The table is 
based on a stress value of 7,500 psi (78 MPa) for 
staybolts that was the value used in the ASME 
Section 1, 1971 Edition. The table identifies 
a calculated MAWP based on measuring the 
staybolt spacing on the crownsheet and the 
minimum diameter of the corroded staybolt. 
See Table S2. 10.4.1. 



S2.10.5 CONSTRUCTION CODE 

To address the many pressure-related compo- 
nents and features of construction encountered 
in firetube boilers, a reprint of the 1971 Edition 
of Section I of ASME Boiler Code, Part PET is 
provided for information only. This section 
may be used for actual repairs/alterations and 
inspection/evaluation of boilers. 



S2.10.6 NOMENCLATURE 

The nomenclature for the terms used in the 
above equations is: 

p = maximum pitch measured between straight 
lines passing through the centers of the 
staybolts in the different rows, which lines 
may be horizontal, vertical, or inclined, 
inches or mm 



R - inside radius of the weakest course of shell 
or drum, in inches or mm 

TS = ultimate tensile strength of shell plates, 
psi (MPa) 

t= minimum thickness of shell plate in the 
weakest course, inches or mm 

P = calculated MAWP psi (MPa) 

S = maximum allowable stress value, psi A07 
(MPa) 

C —2.1 for welded stays or stays screwed 
through plates not over 7/16 in. (11 mm) 
in thickness with ends riveted over 

C=2.2 for welded stays or stays screwed 
through plates over 7/16 in. (11 mm) in 
thickness with ends riveted over 

C =2.5 for stays screwed through plates and fit- 
ted with single nuts outside of plate, or with 
inside and outside nuts, omitting washers 

C =2.8 for stays with heads not less than 1 .3 
times the diameter of the stays screwed 
through plates, or made a taper fit and hav- 
ing the heads formed on the stays before 
installing them and not riveted over, said 
heads being made to have true bearing on 
the plate 

C = 3.2 for stays fitted with inside and outside 
nuts and outside washers where the diam- 
eter of washers is not less than 0.4p and 
thickness not less than t 

Note: The ends of stays fitted with nuts shall 
not be exposed to the direct radiant heat of 
the fire. 

E = the efficiency of the longitudinal riveted 
joint 

The following is a table of efficiencies (E), 
which are the average for the different types 
of riveted joints. 



Type of Riveting 


Lap 


Butt 


Single 


58 




Double 


74 


82 


Triple 


78 


88 


Quadruple 




94 



1 4D 



NATIONAL BDARD INSPECTION CODE • PART Z 



INSPECTION 



TABLE S2.1 0.4 

Maximum Allowable WorS<ing Pressure for Stayed Surfaces per ASME Section 1, PC 46.1 



Thickness 

of Stayed 
Surface 














Staybolt 


Spacing 


(Maximum Pitch) 














B-^iiWK'^v^JTTiiHjS^aS^'^F ^r £ ^"'- * * WJ: *^&f£ ~?&~' m & \ j/£ ^ *' v- ?~* ' r* * 1. "'"'" ■ *'* ? ''-^v**. j^V^J*; £^* 5^js ' ' / 


0.19 
0,2 
0.21 
0.22 , 
0.23 
0.24 
0.25 
0.26 
0.27 
0.21) 
0.29 
0.3 
0.31 
0.32 
0.33 
0.34 
0.35 
0.36 
0.37 
0.38 
0.39 
0.4 
0.41 
0.42 
0.43 
0.44 
0.4.5 
0.46 
0.47 
0.48 
0.49 


85 


65 


1.1 


58 


5.5 


52 


49 


46 


44 


42 


40 


38 


36 


35 


73 


32 


30 


29 




: n 


■ "8 


7 64.. 


bl 


"57.... ■ 


': W 


51 ■ 


.49 2 




44 . 


' 42 


. 40 






: 35 


34 


■ 32 ■■ 


1 01 


80 


75 


71 


67 


63 


60 


57 


54 


51 


49 


46 


44 


42 


40 


39 


37 


.36 


IIS 


<"»:,/" 




7 S 


"1 


' 


66 




59 


' 36. 


31 


51 


,Ci '. 


16 


■ ' 


7.142' 


41 


'39 


125 


96 


90 


8.5 


80 


76 


72 


68 


65 


61 


58 


56 


53 


51 


48 


16 


14 


43 




104 




9' 


■■:..W 


.■\.m 


:i 


^4 





'■■■■iff 


. 64 


•1 


'. 5-8.' 


"' 




■ii 


'7.48.7, 


''■■ft'"' i 


148 


113 


106 


100 


95 


89 


85 


1*0 


76 


72 


69 


61, 


63 


60 


57 


55 


52 


.50 


160: 


" :: 




- w 


,. 


'/w? 


92 • 


11- 


' v. ' .■ 


:. '.78 


■ E '757 . 


- 1 


68 ; 


. 65 


62 




r 


7 : 5.4' 


172 


132 


124 


117 


no 


104 


99 


M4 


89 


8.5 


80 


77 


73 


70 


7.7 


64 


61 


59 


1 :, 








II ' 


■". nl ■ 


106 


01 


<fh : 


, 


■ 87' ' . 


17 


;;q ■ 


". 


. : 72' 




: 66 


63 : 


199 


152 


143 


135 


127 


120 


114 


108 


103 


97 


93 


88 


84 


81 


77 


74 


71 


68 


■ 


3 '»} 


15.3 


: : i44 : 


1 .( 


"129 ; 


;:ii2.. 


116 


.110 7 


-: 




''". 


90 


81' 


•32 


' .' 79 


l> 


■. 72 ; 


ir 


174 


164 


154 


146 


138 


130 


123 


117 


111 


106 


101 


96 


92 


88 


84 


81 


77 


: 242" T . 


,JSgf : : 




Vitf 


,! ".;.4S.5 


"147 ■■■ 


1 ... 






>9 


"'..■^/ -. 


■■4W,: 








■'"■ 


.ii. 


82 


258 


197 


185 


175 


165 


156 


148 


140 


133 


126 


120 


11.5 


109 


104 


100 


95 


91 


88 


■■273'', 




: 197 




: I 7.57 




" 1 "> 7 




I4I 




ria . 


' 1." 




: : - 1 .:.,; 




101 




■ -93 


290 


222 


209 


197 


185 


175 


166 


15- 


149 


142 


135 


129 


I 73 


117 


112 


107 


1 03 


99 


107 


1 


- 


208 


■ 7196 


' 








51 




r.'lifV"'" 


I in 




119 


: rn*., 


11 9 


104 


324 


248 


233 


220 


207 


196 


185 


rii 


167 


159 


151 


144 


137 


131 


125 


120 


115 


110 


" 




-.j. 


..'232./ 


2f9 


:'"2B5:" T 


19.6. : 


■ I'rtrs" 


|-|. 


: ." 10' 


... 1S9 


' 


4. 


i 


n 




l I 


■ 116 


360 


275 


259 


244 


230 


218 


20b 


195 


185 




168 


1 60 


153 


1 46 


139 


133 


128 


122 


; '" 


\J» ■ 


» 




'. 
















...I6p , 


.7,153 7 


II- 


1 ii 


: n 


129 


398 


304 


286 


270 


255 


241 


228 


216 


205 


195 


185 


177 


169 


161 


154 


147 


141 


135 




i o 








■ 253. . 




!2" 




i: 2,0'4 : 


1,9'5 


ll 


. ' : 1 ~ 


' 1 u'l 


: 167 


'. 135 


■ " 


" . 112 


437 


335 


31.5 


297 


280 


26.5 


251 


237 


225 


214 


204 


194 


185 


177 


169 


162 


I55 


149 


'' 4 «0 '■' 




"'.ms;" . 


32 5 


107 


290 


: i?5' " 


! 




2 15 


" 


" ,2i:;'. 




l"4 








.1.63. ; 


502 


384 


361 


340 


321 


304 


287 


272 


259 


246 


214 


223 


213 


203 


194 


186 


178 


171 


524 


..402. 


.■ : ;"|?8.: : 


156 


,,. xib^' 


, jjr..': 


-Or, 


285 




->5" 




2733 


7 222' ■ 




..203 


1 ' 


180 


' l-rt 


547 


419 


394 


371 


350 


.33 1 


314 


297 


282 


268 


255 


243 


232 


222 


212 


203 


194 


186 




v4.J7'k 


H 1 


i 1 


ur. 






• 


294 




i • 


*' 


242 


■■1. 1:1 : 


73 1 




303 




595 


456 


428 


404 


381 


360 


341 


323 


307 


292 


278 


264 


252 


241 


230 


220 


211 


202 



TS = Tensile Strength (55,000) 
t = Thickness of Stayed Surface 
S = 13,800 
P = MAWP 



P = t 2 x SC/p 2 



C = 2.1 if 7/1 6 in. or less 

C = 2.2 if more than 7/16 in. 

p = Maximum Pitch 

For values of t less than or 
equal to 0.4375 in., C=2.1 

For values of t larger than 
0.4375 in., C=2.2 



1 41 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A08 TABLE S2. 10.4.1 LUS Customary Units] 

Maximum Allowable Working Pressure Based on the Load Carrying Capacity of a 
Single Corroded Staybolt 



'■.":■:■■-] 


gJ9| O- 




C 

,'rr-. 




:"cs 
.. Ls. 


"t- 


, : x>.- 


;- : s-4;: 


: -qv 


■fe\ 






'■ vb ■■'■ 




■■Cv' 

■LT,. 


- 


: . "*'. 




■'■(-•J 




r-'l '■ 


;W 


: sj ; 


■Mu 


■p. 


: :- s s: 




-■^■:- 


or: 


'- "5 

>-- 

-o 

■■■■■-■.4» ■■:■■■." 
■ .-a,- ::■■■■■:■. 


Bali ■' -O : 
KM t 




' o.. 
. co.- 


: : .'PPi:' 




;:#■-:■ ■ 


.fN : 




d 

CN':' 


:.- 


' LP," 
.-CC ■ 


(■■■ 


■■"Ld'-' 


: -^--; 


■ LO.:' 


.¥: 


r--. 


■■'■■ 


:~i 


&: 


- 


■■P^ 


"■'.Lb' 


;;;p;:; 


.LTi 


:'-M: 


■:6 

■os 


:#: :: 


M- 


BHsbd 

Kfia ~- J ■ 


:. 


'■<*:■ 
-.-co 
■ si . 


::*£)■■■ 


cb ■ 

■■•*/. 

■fN 


-.":;;■■ 


:cv 


Z 
- 


" 


W-:l 


,- 


:s:: 


ft 


s 


: CN- 

•*■:■■ 


::ln!: 


■OS. 


.■■■., 


''CC'' 


# 


co- 

. P.; 


' : s.- 


'C'.' 


"iS:: 


OS 


■'^-:. 


''■CC':. 


iS: 


3- 
.)■:■ 


ra|: a: ■ 

8sl o ■ 

ISA rn 


X 
; ; ;CO, K 


'■■-.'.CN ' 


r 


. ns 
fN 


:M: 


■.'-0 

■ O: ■ 

..p-r 


"a 


■CO 


i 


■ O ■ 


:;:»■ 


■'Tf-': 


- 


.'■'■'* ■ 


;-!H*:J 
'■1 


'■ rSi. . 




= 


■,i:. 


:'d ■ 


vS 


' ■^■:- 

;o-.. 




■o' 
■.'.cq ; 


'"'M'. 


. CO. 


: 


1' ■. 


^§1 "°s- 

Era : r '' 




'"0-- 

■ IT, 


■■■■■■ 


■■ &: 


i;^:; 


■■■Cv 


.: 


■fs 




'■■^■' : 


::;W:i; 


: 'C7i . 


■^:- 


■ i>) : 
: C-l 


i«sii;; 

■:;S: 


■:'■■'<. 


. 


o 


:S' 


:.-:vb 


;:^)i ; : 


■'■'co'- 


-s : (^i^ 

;.E- 


■'..'co- 


::: : ;:;;;;:: : 

; ; M" ; 

; : ;^:v:.-: 


' LTV. 

■ is;' 


;:^S! 


::S 


Km! o: 




■ '■■<*: 




c;.. 




W;: 


:; :; H 


. sb 




■ : ^t- : ' 


i-.. 


■.'—■' 


■ :-> 
-«■ 


■■CC: 


CiM 


■C: 


■M 


CO 

.OS 


: 


0' : 


':«:' 


■:- ,: C.. 


;is:- : 


sjo' 
;;;iS/; 


-6 ; ! 


.K : 


i 


: 


338 m 






■■:£}.;: 


v.'fN . 




'■cr-^' 
^■■. 




:.LD'' 


. 


■m ^ 




: '-rN ;■ 




.C-: 


■"IS 11 






;.'.-.os 


:^'' 


■:-.-?P-. 




■ K'-'. 


i . 


IS 




■■\D' 




3 : 






.%T: 

■ .o 




■.'SS: 

■ is..: 




:. >-" . 




■:.0- 


■::r- ; :i:. 


■ AC" 
r.| 


:.V 


v-.V"S'.- 


2 


■ ; 5 


■;i^^ 


:>T: 

v.qx 




: -:«j 




■ ee- 
ls 


.;■■. ■ 


■:ls- 


: "^.; 


: tc.-; 




: "S:; 




wSm .as 

O ■■ :(N. 


if?* 


■ : o" 








: r-,- 


/s^ 


- 


-,- 


- 


■" 


.' : ^d'' 
■■'P. 




:-'i>3..-'- 


&i; 


.k; 

" :c °. 




O 1 . 




■■ iri 
: IS : 


• 


■ ' is-- 


i:;:^h 


: ':N. 

■ ; 


:::;^:: 


■■VkV 

': L S'. 


; ;.-■ 




■Sal : — 
EgB a 

H| . 'CM : 


0- 


i":'.'«-£5.':- 

...Ts;- 


,.& 


. Ln : 


u:- 


;' ;"'-C , 


1 


■.fN 


''S 


■\bsV- 
,.o. 


■..■ 


■ -co : : 


"-' 


.-cc. 




■ co.; 


i ■, 


;■ is ■ 


;■::■ 


■■.-co. 


■r. 


'■■ C<4 
.'■'~Q.- 


;:|s;; 


■: CO' 
'..''■is. 


,ft. 


.■'m.: 


:||kS;: 


ip 


E| sea.': 


: , :•" 

I' ri; 


;:-:rn': 


: i:#i; 


- 


" S? ' 


■;.■ ie:; 




' SCvl' ■ 


■■■ ; ':S : . 

Luis 


■'■3: 


:::;m: 


CTi 


: ^ : - 


: '.- r^t 
■.'■»■ 




'-.Ln'- 
: ;s,. 




;co' 

■:^0 




■■'m'.. 
■*o 


% 


■■'■CO.- 


- 


s. 


'"■ 


■.' : o : 




Mii::; 




u 


On ■"""■ 

K| is 


S>Mi 


L,- 


ftp 


■"■OJ:- 


: m¥: 


- 


■p:-: 


P 


i-'^'V 


.'Vm ' 

:.0V. 


S' 


■■■. ^.' .': 

;.;CO ' 




■■■■■ : -c 

:.;-.rs ; 


rt 


;cr> : . 
■;'-:vo. 


Ip: 


-rn':'; 

■■ v^; 


■lip- 


: : co; 

LTl 


ip 


: ■■ rVV 

.L0 : - 


;^p|- 


:' : '0S" 

"...s" : 


: : ': ; ;d;; 
■;!S. 


■'■:'*■ 


% ! 


- : c-: ; 


■■:;■.'.: fc..:. 'v': 

■ : '. ■"«:.■.■■■■■■ 

E 

■\- . re. 


SI — 


;:■■■#;; 


sn. 


i-p 


■ : :':(N':. 


* : 


Vk". 


■:^ : P- 


iv.US'- 
'■..— ■■''■ 


: 


CO... 


■K} 


'■.'■;'rs ; ; 


1 


■o- 

■:.; IS. 




■ : -T: 


- 


■ : .CO . 


r 


■'.ro'- 

■:.-M>.- : 


;l ,^ 


;: CTi : 


::;;:ij:; 


'■'.'in ' 




- 


-r 


;-; : .fii. 


a 

"re 

'■■:: u 


Km \d 


f:^- 


srv 


■ 


= 


:-;;p- 


: ■:':»;' 


J:^ 


■■lab'- 
.:■ — .. 




■'.':. CT).;. 


"■'.r|i ; 


.■■fs'; 


i 


;.::;vp 


- : M:- 


.'■'Li: 


■; ; ^.:: 


■:-'.'n"i'-- 
■■■ | jS. 


:£ 


.'.■^.' 


; : ^- 


'■■LO'. 


"liii: 


: '. : r^j 

'.':■*:' 




■'■:'&■. 


:::; : ^: 


'yn;:. 




Ira ** 
Effl ;/:■ .iri;'. 


■sj 


■;SD- 


::; : . : e:. 


. p. 


;S 


:. o- 
■■:■:■ q> 


-:;p! 


■ C 
cc-' 




R 




: ■■.'-£ ■ 




■.LT) 




S' 


■■:::fe^ 


'OS 

■v^t; 


|::S"; ( 


MS 


:;;0: 


:'^"-- 


: ::: p: 
';:;W: 


..'■'CO 




s 


:::'::^: 


' 




gjal ri-. 


;= 


ft .sC- 

ft— 


r 






'■'■CO.. 




'-/■CO':. 


s 


": : '^i'' 


■H^:: 


■ OS 

.'■ ^ ■ 


■■■ : i^ 


■ rn': 

'■LO 


'..•■. 


: m 


;: sW 


■■.t: 


:::ft 


- 


^S 1 


■■':.'«;■ 
■' ^"'' 


":i: 


'. en ; 


-■ ' 


ft 




- 


Si.§d ■ : p. 


f:^. 


:.,pS;' 


:-:^: 


■■.cC 


i . 


%. 


p" 


' so 


..... 

■ : :^: 


: '.'.-.'c~,; 


" 

■■^A: 


■.'■.' ro ' 
■ :V0,' 


:.^s-:i 


■ CO 

■'■"*■■ 


t\fl:; 


■T 


^4 


■. d.- 
■■^, 


]:i:N: 


ft 


■ ; i : 


'.vn 


;;!;;M 


: m 


:.§■ 


'■'on'' 


: yW:l 


: ": 


■SB : cr>- 
EH -os- 


Jtt 


■ 'CC- 


iflS 


:\0 

'.'■:'.(>'.: 


h:^: 


: .'.o 


■;-^; 


■o : 


...■. 


:L-i 


?--M 


■CO 




■:■■-*■. 


St 
■,i 


'. O 


j|«> : 


■■■':■'■ jjj. 
.'CO' 




:■ :m ■ 


IS 


■■' in . 


■■ ; p; 


■CO- 

■ ■■SI. 


i ■ 

;;i- f ?!;; 


CM 


i;:"^ 


f 




Si^ 


V- K 


"C 


cc- 




■'■c'' 




■.'.■.in 


;* 


■ CO 

'■^ 


?s^ 


■■■■'co 


IS;- 


■ OS- 

■ ro 


i .. 




::;-S ; 
i-il^" 


... rO 


j^ 1 


"o' : 


- 


CO. 




SE' ; 

.-■ <N ' 


i:; :: unL 
: '::;^i: 


■SJ' 


-■■j 




Bsi£ CTv 

El K 


i . . 


'■■: OS 


'€ 


■'o ; 


■^ 


K 


1 ; ■'■. 


■■/ c o. 


^ 


.' .%' 




. ■ -3 s ' 


i^i? 


■■^-. 


'■■'W 


'■■ rsi 
:'.ro'. 


■ ;;P : ; 


■OS.' 




- 


:;;i;i?; 


; cn- 


i 


■:.m': 

■ ?N ; 


:'v^:- 


rN 


Cp 




B2B '">' 




5 


S4; 


R 


Ift 


: ''.' ; f: 


-" 


■ ^ 




°? 


■^ 


■■'*■■ 


.,,.. 


: ':'rn.' 


! :-M- 


cC 

;.',<SJ 




.'.Us 

fN.'. 


:; : ; : :pl; 


'■.rf'..; 

.' s; 


1' 


;''.:n 




■ P' 
:\:n- 


■:pi: 


■'■'0^ 




i-i ; :| 


ijfsg — 


iO-: 


ft- rS 

■: : .LTi 


g 


rs 


■? 








fU 


: ' rr. 


|;^ 


■O 

.-co 


:"%; 


■ : K ; - 


- 


'■LO 


'1 
;ss:^- 


'-'rr- 


;i 


'.■■si. 


... , 


: OS.' 


■■■^p- 


..cc 


,: 


-'.vJ3 


: : N! 


- 


gKAjj " 




;; v-c 


| 


5 


'-?■ 


■'■^ 


: 


::-(N'- 
.'.-'■ ^ 


-- 


. a-: 




■O 
■;(nj 


■|W 


■jlf 


■v. 


s 


", 


■O- 

■;sj 


i^iiSi. 


co 


1 


is 


:, : 


■'■w, 


._... 


■ ; ri-; 


»:#; 


:;!;!(**=! 


Staybolt 
Spacing, 

■.'■. ;■'. in. 


1 tgHHT^^^i^P^feBByiMB "l£* vMm&? ."-*• '.■%MmB 








j: 




>- 




-. 








^ 




-a 




01 




■o 


C 


o 


■~ 


&. 


ec 


o 


c 


u 


u 


M- 


1- 





n. 


k. 


U5 








o 


E 


X5 




rt 


■D 


«i 


II 


II 


T3 


a. 






lift 



•5 a- 

O-Q. 
O II 

© a. 
in > 

11 5 



O 

u 



1 42 



NATIONAL BOARD INSPECTION CDDE • PART 2 — INSPECTION 



A07 Note: The efficiency of a particular joint 
depends upon the strength of the plate 
and rivet, thickness of the plates and the 
diameter of the rivets. The 1971 Edition 
of Section I of the ASME Code, Appendix 
A-1 through A-7, provides a method for 
calculating a specific joint efficiency that 
may be used with the concurrence of the 
jurisdiction. 

FS = Factor of safety 
FS = 4 For stayed surfaces 
A07 FS = 6 For riveted lap joints 

FS = 5 For riveted buttstrap joints 

Note: A Jurisdiction may mandate a higher 
design margin or permit a lower design 
margin, but in no case may the factor of 
safety be less than 4. 



S2.10.7 LIMITATIONS 

a) The maximum allowable working pres- 
sure shall be the lesser of that calculated 
by S2. 10 or the MAWP established by the 
original manufacturer. 

b) The shell or drum of a boiler in which a 
"lap seam crack" extending parallel to 
the longitudinal joint and located either 
between or adjacent to rivet holes, when 
discovered along a longitudinal riveted 
joint for either butt or lap joint shall be 
permanently discontinued for use under 
steam pressure, unless it is repaired with 
jurisdictional approval. 



S2.11 BOILER INSPECTION 

GUIDELINE 

A07 a) The following form may be used as a guide- 
line for documentation and inspection of 
historical boilers. Jurisdictions may require 
additional inspections and documentation 
otherwise noted in this guide. The owner 
and Inspector should be aware and under- 
stand jurisdictional requirements where the 
historical boiler will be operated. 



Jurisdiction Number 



Owner 



Location 
Make 



Year 



Engine No 

Heating Surface 

Design Pressure 

Current Operating Pressure 
Inspector 



Safety Valve(s) Setting 



Total Safetv Valve Capacity 



b) As a minimum, the inspection shall include 
consideration of the following: 

1 ) Smoke Box 

a. Front Tubesheet 

1 . Check condition of front 
tubesheet and thickness 
around handhole openings. 

2. Check condition of threaded 
openings and plugs. 

3. Check condition of rivets 
between front tubesheet and 
barrel. 

b. Tubes 



1 . Are tubes beaded back to the 
tubesheet? 

2. Are there signs of leakage? 



1 43 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 



A07 



c. Check condition of smoke box shell 
(especially around lower surfaces). 

d. Check inside condition of barrel 
and outside diameter of tubes for 
corrosion and scale. 

e. Check back side of tubesheet (espe- 
ciallyarea in contact with handhole 
gasket and area where tubesheet 
joins barrel). 

f. Check tubesheet supports (through 
stays, supports or strong backs). 

g. Check inside rivet heads on lap or 
buttstrap joints, if possible. 

h. Check front bolster (front axle) at- 
tachment points inside barrel. Note 
thinning of the lower smokebox 
section of the barrel is critical if 
the steering bolster attaches fully 
or partially to this thinned area. 

2) Barrel (shell) 

a. Check front bolster attachment 
points on the outside of the barrel, 
both within and without the present 
boundary. 

b. Check condition of tubesheet rivets 
on outside of barrel. 

c. Check condition of threaded open- 
ings and plugs in openings. 

d. Check radius rod attachment 
point. 

e. Check attachment points of studs, 
castings, brackets, accessories, 
etc. 

f. Check piping and nozzle openings 
on shell (feedwater nozzles, steam 
outlet, water column, etc.). 



g. Check handhole openings in bar- 
rel. 

h. Lap seam or buttstrap 

1 . Check for leakage around 
riveted seams and joint rivets. 

2. Confirm joint efficiency based 
on number of rows of rivets 
and type of joint. 

i. Identify and check any external con- 
tour that does not appear normal. 

j. Insulation or Insulation Jacket (lag- 
ging) 

1 . Does jacket cover any critical 
areas or make them difficult to 
observe? (Normally the jacket 
will need to be removed for 
inspection of the barrel.) 

2. Is barrel pitted or corroded 
under jacket? 

3) Wrapper Sheet 

a. Check handhole openings (material 
thickness, gasket area, etc.). 

b. Check for seepage around attach- 
ment points (wing sheets, axle sup- 
ports, etc.). 

c. Check condition of riveted seams 
joining wrapper to throat sheet and 
rear head. 

d. Check condition of riveted seams 
joining throat sheet to barrel. 

e. Check external shapes or contours 
that do not appear normal. 

f. Check for seepage around staybolt 
heads. 

g. Check condition of staybolt heads. 



1 44 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



h. Check condition of threaded 
openings. (May need to remove 
nipples and plugs.) 

i. Check internal surfaces for cracks, 
pits, material thickness, and scale. 

j. Check staybolt thickness and condi- 
tion. 

A07 k. Check for scale and mud buildup 

in waterlegs and wet bottoms. 

I Check for buildup of dirt and grease 
between or behind attaching brack- 
ets such as wing sheets. 

m. For dry bottom boilers 

1 . Check riveted scams at bot- 
tom of waterlegs in ash pan 
area (ogee ring). 

2. Do you need to remove ash 
pans and grates to observe 
above seams? 

3. Check condition of grate sup- 
port brackets. 

n. For wet bottom boilers 

1 . Check ash pan area for pits 
and staybolt head condition. 

2. Check inside bottom of wrap- 
per and staybolt condition. 

3. Check condition of lap seam 
in wrapper. 

4. Check condition of ash pan 
drain tube if present. 

A07 5. Check condition of drain plug 

and plug threads. 

A07 6. Check condition of studs, es- 

pecially studs holding hitches 
to the bottom sheet. 

o. Check for condition of blowdown 
valve. Check for size and type. 



4) Steam Dome 

a. Check for condition of drain back 
holes in shell if possible. 

b. Check condition of main steam stop 
valve. 

c. Check condition of piping on the 
steam dome and the condition 
of the steam outlet piping on the 
steam dome. 

d. Check condition of the steam dome 
seams and seams between the 
steam dome and the boiler shell. 

1 . Is seepage present? 

2. Can interior seams be ob- 
served? 

e. Check the condition of pressure 
gage 

1 . Is there a siphon and what is 
its condition? 

2. Is the gage readable from the 
operator's position? 

3. Has the gage been calibrated 
or checked against another 
gage? 

4. If a shutoff valve is present, 
its handle shall indicate open 
position, 

5. Cage checked for correct A07 
range and pressure. 

f. Check for condition of safety 
valve. 

1 . Does the safety valve have its 
own inlet/outlet piping with 
no intervening block valves 

and no possibility of isolation? A07 

2. Check that the inlet pipe size 
is not smaller than the valve 
inlet size. 



1 45 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



3. Check that the outlet pipe size 
is not smaller than the valve 
outlet size. 

4. Is the safety valve a National 
Board capacity certified, ASME 
"V'VNational Board "VR" 
stamped valve of proper set 
pressure and capacity rating 
for the boiler heating surface? 

5. Does the safety valve have a 
try lever (hand lifting lever)? 

6. Is the safety valve sealed with 
factory seals at the top pres- 
sure adjustment cap and at 
the blovvdown ring adjust- 
ment point? 

5) Water Column and Cage Class 

a. Is the gage glass calibrated to the 
level of the crownsheet? 

b. Check condition of try cocks, gage 
glass stop valves, gage glass drain 
valve, and water column drain 
valve. 

c. Check condition of gage glass 
(cracks or scratches). 

d. Check the upper and lower gage 
glass packing for signs of leakage. 

6) Firebox 

a. Check for bulging between stay- 
bolts and warping of the boiler plate 
(what caused this?). 

b. Check riveted seams around the fire 
door. 

c. Check for sediment buildup over 
the fire door opening at the rear 
head. 

d. Check for sediment buildup over 
the peephole opening in the wrap- 
per sheet (where applicable). 



e. Check condition of fusible plug. 
(The plug must be removed for 
observation). 

1. Is it stamped ASME standard? 

2. Check condition of top 
surface for scale and bottom 
surface for tin corrosion. (May 
need to brush it off.) 

3. Check for signs of leakage be- 
tween the tin center and brass 
casing. 

f. When the fusible plug is removed, 
check crownsheet thickness at that 
location and thread condition. Are 
weld repairs required? 

g. A fireside fusible plug must project 
a minimum of 3/4 in. (17.8 mm) 
into the waterside. 

h. Fireside fusible plug may not extend 
into fire area more than one 1 in. 
(25 mm) 

i. A gage glass calibration can only be 
done when the crownsheet and fus- 
ible plug and gage glass can be seen 
and measured. A recommended 
minimum water level may be de- 
termined as follows: With engine 
(boiler) sitting on level ground and 
water just observable at the bottom 
of the gage glass, the crownsheet 
should be covered by at least 2-1/2 A07 
in. (64 mm) plus of water on a full- 
size boiler. 

j. Check staybolt condition, especial- 
ly near top surface of crownsheet. 

k. Check through stays, strong backs, 
knee braces, etc., on rear head. 

I. Check handhole openings, threaded 
openings and plugs in rear head. 



1 46 



NATIDNAL BOARD INSPECTION CODE • PART Z — INSPECTION 



m. Check condition of firebox tubesheet 
and check if tubes are beaded back 
to the tubesheet. 

n. Check condition of staybolt heads 
inside the firebox. 



8) UltrasonicThickness Testing (every fifth 
year). 

9) Hydrostatic Pressure Test (minimum 
every three years or as required by the 
Jurisdiction). 



A07 



A07 



o. Check condition or design of 
crownshcet. Is it flat-topped or able 
to trap water? Is it free of scale? 

7) External Plumbing (see S2. 7.1) 

a. Is black pipe (as opposed to galva- 
nized pipe) used throughout? 

b. Check for use of schedule 80 black 
pipe required between boiler and 
first valve. 

c. Are fittings and valves of proper 
pressure rating for maximum allow- 
able working pressure? 

d. Are isolation valves present to shut 
off individual system lines (blower, 
injector, main steam, blowdown, 
etc.)? 

e. Are two separate feedwater systems 
present and operable? 

f. Check piping for freeze damage. 

g. Are piping support brackets present 
where needed? 

h. Fittings dates are to be stamped, 
stenciled, or recorded on boiler 
records (boiler log). 

i. Piping shall have a 20-year life, 
except for the main steam line, 
which shall be periodically evalu- 
ated as to remaining service life. 
As an alternative, all boiler piping 
may be ultrasonically examined for 
adequate thickness to determine 
the remaining service life. 



a. Hydrostatic pressure test should be 
between maximum calculated al- 
lowable working pressure; and 1 .25 
times maximum allowable working 
pressure with metal temperature at 
60°F-120°F. 

b. A calibrated pressure gage shall be 
used when hydrostatically pressure 
testing a boiler. The boiler gage 
may be compared (calibrated) with 
the calibrated pressure gage at this 
time. 

c. All safety valves shall be removed 
during the hydrostatic testing of the 
boiler. 

1 0) Safety Valve Testing ^7 

a. Safety valves should be removed 
from the boiler for testing and/or 
repair at intervals required by the 
Inspector or the Jurisdiction. 

b. Safety valves may be try lever 
checked for operability with the 
boiler under steam pressure of at 
least 75% of the set pressure of the 
safety valve. 

c. Safety valves may also be tested 
initially, periodically and after any 
repair or adjustment as noted in 
the External Operating Test listed 
below. 

11) External Operating Test (every third A07 
year) 

a. The safety valve should be tested by 
having the operator raise the boiler 



1 47 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



pressure to the safety valve popping 
point and popping point pressure 
and blowdown observed to be 
within manufacturer's tolerances. 

b. Feedwater devices (two injectors, or 
one injector and one pump) tested 
for operability. 

c. Gage glass stop and drain valves and 
gage cocks checked in service. 

d. Blowdown valve(s) tested as op- 
erational and discharging to a safe 
location. 

e. Operation of the steam engine by 
the operator satisfactory, including 
a driving test. 

f. The external operating test to be re- 
corded in the boiler records (boiler 
log). 



S2.1 2 INITIAL BOILER CERTIFICATION 

REPORT FORM 

Form C-1 may be used to document the initial 
inspection for historical boilers. (Form C-1 is 
located at the end of this supplement.) 



A07 S2.1 3 GUIDELINES FOR HISTORICAL 

BOILER STORAGE 

The historical boiler guidelines published here- 
in list the general recommendations for storage 
of historical boilers. The exact procedures used 
by the owner/operator must be based on the 
conditions and facilities at the storage facility. 



1) The anticipated length of time the his- A07 
torical boiler will be stored; 

2) Whether storage will be indoors or 
outdoors; 

3) Anticipated weather conditions during 
the storage period; 

4) The availability of climate-controlled 
storage; 

5) Type of fuel used; and 

6) Equipment available at the storage 
site. 

b) Indoor storage can be categorized into A07 
two types: indoor with climate control and 
indoor without climate control. 

c) Outdoor storage can also be categorized A07 
into two types: outdoors during a warm 
time of year or in a geographic location 
where it can reasonably be expected to 

be above freezing during storage, and 
outdoors during a time period or in a geo- 
graphic location where it can be expected 
that freezing temperatures will occur during 
storage. 

d) Historical boilers may be stored using the A07 
"wet method" or the "dry method." 

e) Before any method of storage, the boiler A07 
must be thoroughly washed out with mud 
and scale removed from the mudring, 
crownsheet, bottom of the barrel, and the 

top of the firing door. 



S2.1 3.1.1 WET STORAGE METHOD 



A07 



A07 S2.1 3.1 STORAGE METHODS 

a) The methods for preparing a historical 
boiler for storage depend upon several fac- 
tors, including: 



a) When utilizing the "wet storage method," 
the boiler is completely filled with treated 
water to exclude air. 

Note: This method cannot be used if the 
historical boiler is exposed to freezing 
weather during storage. 



i 4a 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 b) Chemicals may be added to the storage 
water to further inhibit corrosion. How- 
ever, depending on the chemical used, the 
treated water may have to be disposed of as 
a hazardous wasle to prevent chemical con- 
lamination of the surrounding property. 

A07 c) The procedure applies only to the sections 
of the boiler that contain water. The firebox 
interior, cylinders, piping, and auxiliary 
equipment of the historical boilers still 
require draining, preservation, and dry 
storage. 



A07 S2.1 3.1 .2 DRY STORAGE METHOD 

a) When utilizing the; "dry storage method" 
the boiler is completely emptied of water, 
dried out, and allowed to stand empty. 
Several variations of the "dry method" may 
be used. These include but are not limited 
to: 

1) Air tight storage with moisture absor- 
bent placed in trays in the boiler; 

2) Air tight storage with the boiler filled 
with inert gas to exclude oxygen; 

3) Open air storage with the mudring 
washout plugs or handholes removed 
to enable air circulation for evaporation 
of formed moisture. 

b) Each variation has positive and negative 
points that must be taken into account 
before use. If the boiler is filled with inert 
gas such as nitrogen, care must be taken 
because this method can result in asphyxi- 
ation of personnel if the gas escapes the 
boiler through a leaking valve, washout 
plug, or handhole and enters a pit, sump, 
or enclosed room. In addition, the boiler 
must be completely vented to remove gas, 
then tested and declared gas free before 
personnel may enter. 



c) Although the use of dry storage with several A07 
washout plugs or handholes removed for air 
circulation is the most common method, 
there are some potential drawbacks. The 
boiler interior may be subject to moisture 
forming from condensation created from 
humidity changes in the ambient air. Small 
animals may take up residence inside if 
screens are not used to cover handholes 

or washouts. 

d) Before storage, the boiler must be thorough- A07 
ly washed out with mud and scale removed 
from the mudring, crownsheet, bottom of 

the barrel, and top of the firing door. Any 
mud or loose scale left in the boiler will 
retain moisture leading to corrosion. After 
washing, water must be removed and the 
boiler dried before storage. A portable gas 
or electric heater placed in the firebox to 
aid evaporation and drying along with a 
vacuum used to siphon water out via the 
lower washout plugs or handholes is rec- 
ommended. 

Note: Use of the drying out procedure of A07 
building a small wood fire in the firebox is 
not recommended because of the danger 
of overheating the firebox sheets. 

e) The typical railroad dry storage method A07 
required blowdown of the boiler until 
empty while steam pressure registered on 

the gage and removal of the washout plugs 
or handholes while the shell plates were 
hot and there was no steam pressure. This 
allowed the heat remaining in the boiler 
plates to evaporate remaining water in the 
boiler. However, this method may result in 
staybolt damage from temperature change 
and requires extreme care, if used. 

f) Oil should not be applied to the interior A07 
surfaces of the boiler because it is difficult 

to remove. Further, the oil must be removed 
before steaming or it will form scale and 
contribute to foaming. 



1 4-9 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



A07S2.13.2 RECOMMENDED GENERAL 

PRESERVATION PROCEDURES 

A07 a) When the historical boiler is under steam, 
inspect piping, fittings, and appliances for 
steam and water leaks that may introduce 
moisture into the lagging. Repair leaks as 
necessary and remove wet lagging insula- 
tion. 

A07 b) Remove grates and ash pan bottom if dry 
bottom. Remove washout plugs and hand- 
hole plates. Mark handhole plates and 
washout plugs for proper relocation. 

A07 c) Thoroughly wash the boiler and firebox and 
remove mud and scale from the mudring, 
crownsheet, bottom of the barrel, and top 
of the firing door. Any mud or loose scale 
left in the boiler will retain moisture leading 
to corrosion. 

A07 d) To protect the boiler interior during stor- 
age, dry the boiler by using compressed 
air to blow out as much water as possible. 
A portable heater placed in the firebox to 
warm the boiler to 200°F (95°C) along with 
a vacuum used to siphon water out via the 
lower washout plugs or handholes can aid 
evaporation and drying of any moisture 
that collects in low or impossible-to-drain 
locations without harming the sheets. 

A07 Caution: To prevent a build up of steam 
pressure during the drying process, an 
opening in the upper part of the boiler 
should be opened to enable the moisture 
to escape. In addition, the driving wheels 
should be blocked and the throttle and 
cylinder cocks should be opened to permit 
any steam that forms to escape. 

A07 After drying, it will be necessary to either 
vent the boiler or to place containers of des- 
iccant inside the boiler through the dome 
cap to absorb any condensation that may 
occur during storage. Venting the boiler to 



allow air circulation is accomplished by A07 
leaving two or more of the lower washout 
plugs or handholes out and opening the 
vent valve on the top of the boiler. A vent 
line consisting of two 90 c elbows and pipe 
nipples should be installed in the vent valve 
to locate the opening to the downward di- 
rection in order to keep rain or snow from 
entering the open valve. 

e) To prepare a historical boiler for storage, A07 
the following should be completed: 

1) If the historical boiler will be stored A07 
outdoors, inspect the boiler jacket and 
confirm it is tight with no gaps leading 
into the lagging or shell. Pay close at- 
tention to areas at shell openings such 

as for studs, safety valves, etc. Repair 
gaps or damaged jacket sections as nec- 
essary. Consideration should be given 
to covering the entire historical boiler 
and equipment with a tarp. Otherwise, 
jacket openings should be covered to 
prevent the entrance of rain or snow. 
Where necessary, apply a waterproof 
covering over the exposed or open 
sections. 

2) If the historical boiler will be stored A07 
outdoors, the smokestack should be 
sealed by applying a wood and sheet 
rubber cover held in place by clamps 

or a through bolt. 

3) If the historical boiler will be stored A07 
outdoors, the safety valves should either 

be covered or removed, with plugs or 
caps installed in the holes if the valves 
are removed. The governor and lubrica- 
tors should be covered. 

4) Clean tubes using tube brush or scraper. A07 
After cleaning use a long air nozzle or 
vacuum to remove any loose coal or 
ash. 



1 5D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07 5) Empty and clean the smokebox and 
front tubcsheet of all coal, ash, or burnt 
oil. This work is especially critical at 
the bottom section of the smokebox 
and front tubesheet rivet flange. The 
smokebox door should be sealed by 
applying a gasket or sealant and any 
other air openings in the smokebox 
sealed. The exhaust nozzle should be 
sealed by applying a wood and sheet 
rubber cover held in place by clamps. 

A07 6) Thoroughly clean the firebox sheets of 
coal, ash, and clinker. 

A07 7) The potential for corrosion of the 
smokebox interior, front tubesheet, and 
fireside of the firebox sheets can be 
further minimized by applying coating 
of light oil, outdoor paint, or primer. 
Inspection of the smokebox, front 
tubesheet, and firebox sheet must be 
accomplished before painting since it 
will cover up many types of defects. The 
coating will burn off quickly when the 
historical boiler is returned to service;. 

A07 8) Empty and clean the grates and ash 
pan of coal and ash completely. This 
work is especially critical at the sec- 
tions between the grate bearers, rivets, 
and firebox sheets; and from the grate 
segment air openings. 

A07 9) Appliances and piping that might con- 
tain water or condensation should be 
drained and blown dry using dry com- 
pressed air. Remove injectors and store 
in a warm place. Refer to S2. 13.3, Use 
of Compressed Air to Drain I listorical 
Boiler Components, for details. 

A07 10) The cylinder castings, valve cavities, 
and steam lines must be drained of 
moisture and blown dry. Typical meth- 
ods include: 

a. Pressurize the boiler with com- 
pressed air. Using the throttle to 



regulate the airflow, allow the air 
to blow through the dry pipe and 
discharge into the cylinders. The 
cylinder cocks must be open. 

Note: This may have to be per- A07 
formed several times to discharge 
the moisture from the cylinders and 
steam pipes. 

Refer to the S2.13.3, Use of Com- 
pressed Air to Drain Historical 
Boiler Components, for additional 
information. 

11) Drain and wash tender water spaces. A07 
The tank should be inspected afterward 
and any remaining water removed by 
siphon or vacuum. When dry, spray 

the water space with outdoor paint or 
a commercial rust preventative. Oil 
should not be used. Drain and dry the 
tender tank hoses and clean screens. 

12) On coal or wood burners, remove coal A07 
or wood. Spray any exposed surfaces 

of the tender fuel space with outdoor 
paint or a commercial rust preventative. 
If the historical boiler is to be stored 
outdoors for long term, cover the coal 
space with a tarp or a roof. 

13) After cleaning thoroughly, coat con- A07 
necting rods, cross heads, valve gear, 
guides, piston rods, and exposed feed- 
water pump components with water- 
resistant grease or a rust preventative. 

If the historical boiler is to be stored 
outdoors for long term, grease should 
be applied to junction of rod and pin 
in valve gear and rods to prevent water 
entering. 

14) If the historical boiler is moved after A07 
this is applied, it will be necessary to 
reapply the coating to piston rods and 
guides. 



1 5 i 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07 Note: Heavy oil or unrefined oil such 

as any of the Bunker types (Bunker 6, 
etc.) should not be used for preservation 
of any components because the sulfur 
contained in it can accelerate corro- 
sion. Standard motor oil or journal oil 
will not stick to and preserve wetted 
surfaces. Surfaces to be so coated must 
be dry. If moisture is a problem, steam 
cylinder oil should be applied. 

A07 15) All openings in the boiler should be 
covered to ensure water and contami- 
nants can not enter the boiler. Hand- 
holes and plugs left out for air circula- 
tion should be covered with screen to 
prevent small animals from entering 
and taking up residency in the boiler. 
Secure all openings and covers on the 
top of the water tender to prevent ac- 
cidental opening with the potential for 
water and contaminants to enter. 

A07 16) If the historical boiler is to be stored 
outdoors with questionable or no 
security, remove and store all cab 
gages, water glasses, lubricators, brass 
handles, whistle, headlight, tools, spare 
parts, and any other items that thieves 
or vandals might attack. 

A07 1 7) Inspect stored historical boiler regularly 
for signs of rust, corrosion, damage, 
deterioration, vandalism, or animal 
invasion and immediately take any 
corrective measures necessary. 



b) The air compressor must be equipped A07 
with a suitable filter to enable it to supply 
oil-free air because the introduction of air 
that contains oil into the water/steam parts 

of the boiler will promote the formation of 
scale and water foaming when the historical 
boiler is returned to service. 

c) The air compressor must be a large enough A07 
size to provide the volume and pressure of 

air required. 

d) If the boiler is pressurized with compressed A07 
air, the air pressure must be raised slowly 

to prevent distorting or overstressing the 
firebox sheets or staybolts because the 
normal expansion of the boiler that occurs 
under steam pressure is not present when 
air pressure is used. 

e) When pressurizing the boiler with air, the A07 
pressure should never exceeded 3/4 of the 
maximum allowable working pressure. Air 
shall never be used for pressure testing the 
boiler. 

f) Components are drained by pressurizing A07 
the boiler to 1/2 to 3/4 of the maximum al- 
lowable working pressure with compressed 

air, then operating each component indi- 
vidually until the exhaust from it contains 
no moisture. 

g) When necessary, specific pipe lines can be A07 
drained by breaking the line at each end, 
attaching the air line to it directly then 
blowing the line out. 



A07S2.13.3 USE OF COMPRESSED AIR TO 
DRAIN HISTORICAL BOILER 
COMPONENTS 

A07 a) The process of using air pressure to drain 
and empty auxiliary components such as 
the cylinders and piping completely of 
water offers several advantages over other 
methods. 



S2.13.4 RETURN TO SERVICE A07 

a) When returning a historical boiler to ser- 
vice, the boiler, firebox, and tender tank 
shall be ventilated to remove potentially 
hazardous atmosphere from the firebox 
interior before personnel enter it. In addi- 
tion, the atmosphere in the firebox shall be 
verified to be safe for human occupancy 



1 52 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07 before personnel enter it. For the boiler 
this can be accomplished by removing the 
washout plugs or handholes and placing a 
fan or air blower on top of a steam dome 
opening to force air into the boiler. For the 
firebox this can be accomplished by open- 
ing the smokebox door and firebox door 
and placing a fan or air blower at either 
location to force air through. Failure to do 
this could result in asphyxiation of the first 
personnel to enter the boiler or firebox. 

A07 b) Perform a complete boiler flush to remove 
scale that has flaked off during storage as 
a result of the expansion and contraction 
of the metal due to temperature changes 

A07 c) Clean handhole plate gasket surfaces (both 
boiler and handhole plate). These surfaces 
must be flat and free of scale, rust and dirt 
in order to seal. 

A07 d) Inspect feedwater inlet connection to boiler. 
There should be a tee at each inlet; remove 
plug and inspect for lime deposits and clean 
if necessary. This should be done once a 
year, more often if conditions warrant it. 

A07 e) Remove gage glass and valves, and inspect 
these connections lime deposits and clean 
if necessary. This should be done once a 
year, more often if conditions warrant it. 

A07 f) After inspection, replace glass (clean if 
necessary). Also inspect gage glass sealing 
washers and replace if necessary. 

A07 g) During cold weather, the historical boiler 
should be moved into a heated area and 
the boiler allowed to warm up in the air for 
several days until it is the same temperature 
as the air. 

A07 h) The initial fire up should be done slowly to 
allow even heating of the boiler. 

A07 i) Before movement, the cylinder(s) should 
be warmed up by allowing a small quantity 
of steam to blow through them and out the 



cylinder cocks and exhaust passagc(s). This 
is necessary to reduce the stress in the cast- 
ing from thermal expansion of the metal. 

j) Steam should be discharged through the A07 
cylinder cocks for several minutes to aid 
removal of any solvent, debris, or rust that 
may have formed in the steam pipes, cyl- 
inder, valve chest, and dry pipe. 

k) All appliances should be tested under A07 
steam pressure before the historical boiler 
is moved or put under load. 



S2.14 



SAFETY PROCEDURES' 



A07 



This chapter of text covers procedures if certain 
situations or emergencies that may occur. 



S2.14.1 



EXPERIENCE 



A07 



a) Reading check lists and procedures can be 
of some value to get you thinking about 
what you are doing, but nothing can re- 
place the experience gained by working 
beside conscientious and knowledgeable 
engineers. Ask questions, observe, read, 
listen, study, and think. 

b) Safe operations depend upon thorough at- A07 
tention to detailed routines. Having proce- 
dures thought out, planned, and practiced 
before they are needed could minimize 
accidents and improve public safety. Know 
your abilities as well as the machine's limi- 
tations that you are operating. In most cases 
knowing and keeping your machine in top 
operating condition can prevent most emer- 
gency situations from occurring. However, 
sometimes problems or situations beyond 
your control do occur. In any situation the 
first rule to remember is to keep a cool 



3 Copyright © 2004 Wisconsin Historical Steam Engine As- 
sociation. All rights reserved. The material in this text written 
by the Wisconsin Historical Stearin Engine Association may not 
lie reproduced in any form without written permission of the 
author and the Wisconsin Historical Steam Engine Association. 



1 53 



NATIDNAL BDARD INSPECTION CODE • PART Z 



INSPECTION 



head. Haste and panic can never solve any 
emergency. 

A07 c) Don't be afraid to ask for help or advice. A 
lot of shows or public demonstrations are 
having a designated individual in the area 
to ensure safe operation and assistance 
should a problem arise. 



A07S2.14.2 STOPPING ENGINE IN AN 
EMERGENCY 

A07 a) Know how to stop your engine suddenly. 
For example, if someone or something runs 
out in front of you or some problem hap- 
pens with whatever you're belted up to: 

1 ) Close throttle. 

2) Reverse valve quadrant position. 

3) Open throttle for a moment (this will 
quickly stop your engine). 

4) Close throttle. 

5) Open cylinder cocks. 

A07 b) Steam traction engines do not have brakes, 
so this is a maneuver worth knowing and 
practicing. However, it should be practiced 
with the dome valve shut. As this method 
of stopping your engine tends to be very 
hard on gears and castings! In regards to 
belt work, it is extremely important that you 
give your total undivided attention to what 
you are belted up to! Be prepared to shut 
down quickly should something happen, 
you are supplying the; power to what you 
are running. Only you can stop the power! 
Be Alert! 



glasses do break. If your machine is operating aq7 
when a break occurs: 

a) Close throttle. 

b) Set valve quadrant to neutral (middle 
notch). 

c) Disengage clutch. 

d) Close damper. 

e) I ocate bottom water glass valve and shut 
off. 

1) The first four procedures will be difficult 
if your water glass is mounted back by 
the operator's platform. 

2) The bottom water glass valve is essential 
to locate and close first. This valve is 
below the waterline and can take the 
water dangerously close to the crown- 
sheet if water is allowed to escape 
unchecked. This is where having the 
automatic type gage valves would be 
most desirable. Most traction engines 
do not have automatic type gage valves. 
Caution must be exercised at this time 
because 300 degree steam and water 
will be spraying in every direction! You 
won't be able to see much of anything 
except a cloud of water vapor, so use a 
shovel or a coat or something to deflect 
the spray so you can find that lower 
valve. 

f) Next, close the top gage valve, this one A07 
should just be blowing steam and obscuring 
visibility. There is no serious problem with 
steam being released because this valve is 
above the water line. 



S2.14.3 WATER GLASS BREAKAGE 

A07 This can be avoided by having a properly guard- 
ed water glass to prevent objects from coming 
in contact with the glass itself. However, water 



g) Next, use try cocks to determine water level A07 
of boiler. If bottom try cock blows water, 
then you can inject water and move to re- 
place water glass. However, if bottom try 
cock does not blow water, and only blows 
steam, do not inject water and proceed to 



1 54 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



kill fire immediately! Do not move engine! 
Another method of determining your water 
level in the boiler other than your try cocks 
is to wet down a burlap sack and lay it on 
the barrel part of the boiler. Quickly pull 
it away and you will see a "sweat line" of 
where your actual water level is. 



A07 S2.14.4 RUNAWAY ENGSNE AND 
GOVERNOR OVER SPEED 

A07 a) Probable causes: governor malfunction. 
Most times the governor belt either slips 
or breaks. Know your governor belt condi- 
tion and keep its tension snug but not loo 
tight. Also, packing nut could be too tight 
causing a binding on valve spindle, more 
often though this will cause engine to not 
respond to load and usually will not "run- 
away." 

A07 b) What to do in a runaway situation: Again, 
I stress never leave the operator's platform 
while engine is at governed speed. In the 
case of a runaway engine: 

1 ) Quickly close the throttle. 

2) Move forward/reverse lever to center of 
quadrant. 

3) Open cylinder cocks. 

4) Close dome valve. 

5) Close damper and steam down (this is 
not a boiler emergency once engine has 
stopped there should be no danger). 

A07 c) In the unlikely event the throttle was to 
jam in conjunction with governor malfunc- 
tion: 

1) Move forward/reverse lever to center 
of quadrant. This will stop the engine 
even though steam is still being sent to 
the valve chest. 



2) Close the dome valve; this would be the 
same as closing the throttle. Steam flow 
would then be stopped and the engine 
should be safe. 

3) Close damper and steam down. 



S2.14.5 KILLING A FIRE A07 

This is an important procedure to know, should 
a low water situation ever occur. 

a) Close all dampers. This will stop incoming A07 
air which supports fire. Capping the smoke- 
stack is also an additional way of checking 
draft to fire. However, it will cause a lot of 
smoke to emit around fire door. 

b) Shovel dry sand or dry earth on the fire, A07 
this should immediately cool the fire to a 
safe level. A good idea would be to have 

a pile of dry sand or dirt in or around your 
steam engine area should a situation occur. 
Also it is important to remember that when 
•trying to extinguish fire, never stir the fire; 
this will only intensify the fire's heat. 



c) Close the fire door. 



d) Close the dome valve. 



A07 



A07 



e) Leave the engine alone. It is especially im- A07 
portant not to move the engine as this could 
slosh water onto a possibly overheated 
crownsheet. 



S2.14.6 INJECTOR PROBLEMS A07 

This is probably the number one problem oc- 
curring with boiler operation. An injector can 
be a very finicky device. Being able to identify 
the reasons why it's not working is one of the 
most important things a good steam engineer 
needs to know! Here are some various prob- 
lems and some of their causes. 



1 55 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07 a) Failure to raise water from supply tank 

1) Suction pipe clogged or tank supply- 
valve turned off. 

2) Leaks in suction pipe or hose, allowing 
air to enter above the level of water 
supply. This is a common problem 
when rubber or plastic hoses are used 
on suction side of injector. 

3) Water supply too hot. Hot water will 
prevent injector from lifting water. 

4) Obstruction in the lifting or combining 
tubes of the injector. 

A07 b) Injector lifts water but will not force it into 
the boiler 

1 ) Choked suction pipe or strainer/incom- 
plete obstruction. 

2) Supply valve not opened all the way. 

3) Boiler valve closed. 

4) Boiler check valve stuck closed. 

5) Obstruction in delivery tube on injec- 
tor. 

6) Leaking injector overflow check valve. 

7) Injector choked with lime. 

A07 c) Some various injector problem scenarios 

1) In most cases you have a hot injector 
because of improper operation. This 
is where a removable rubber hose on 
your water suction is handy. Remove 
hose, turn steam valve on to injector 
and put your thumb over suction side 
of injector. You should feel a smooth 
steady suction. If not, wrap a rag around 
injector body and soak rag with cool 
water, your objective is to cool down 
the injector. Now turn steam back on to 



injector allowing cool air to suck into 
injector, at the same time place suction 
hose back onto water supply line and it 
should go. Remember to tighten suction 
side connections so you don't lose your 
vacuum. 

2) If injector still does not lift after trying A07 
the previous instructions, it probably 

has some foreign matter in the lifting or 
combining tube. Simply remove bottom 
square nut on injector body, taking care 
not to lose flat washer that will come 
out with injector combining tube, clean 
and reinstall. This should restore injec- 
tor to perfect working order. 

3) When having injector problems, watch A07 
your injector overflow. Steam only and 

no water at overflow usually is an in- 
dication of a water lifting problem (no 
water to the injector). Steam and water 
at the overflow is usually a delivery 
problem meaning your injector is lifting 
water but not forcing into boiler. 

4) The problem with delivery is usually A07 
associated with a stuck boiler check 
valve. After assuring yourself that the 
isolation valve to the boiler is open, 

try lightly tapping on the boiler check 
valve. More than likely though you will 
have to disassemble and clean boiler 
check valve, there is probably scale 
holding check valve from opening. This 
can be done with steam pressure on 
the boiler, providing the valve to the 
boiler holds pressure and the boiler 
check valve has been properly piped 
in. Much the same, a boiler check valve 
may not close, causing steam and hot 
water to blow back through injector 
and into your feedwater tank. Again, 
you would have to turn off the valve to 
the boiler, disassemble and clean the 
check valve. If the injector will not force 
water into the boiler, there may be an 
obstruction in the delivery/combining 
tube of the injector. Remove bottom nut 



1 56 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



of the injector, disassemble and clean 
as explained earlier. 



S2.14.7 FOAMING OR PRIMING BOILER 

A07 a) As mentioned previously in this text, a 
foaming boiler is usually caused by dirty or 
impure water in the boiler. Oils, detergent, 
etc., are the biggest problems and have no 
business being on the waterside of a boiler. 
A good rule of thumb is "If you wouldn't 
drink it, don't put it in your boiler." Foaming 
can be especially bad because you have 
no way of discerning your water level. The 
water glass and try cocks will appear full. 
Foaming is usually really intensified with 
a heavy fire and a heavy engine load. The 
best thing you can do is to reduce or stop 
your engine load and reduce your fire until 
it settles down, steam down, wash out your 
boiler, and refill it with clean water. The first 
indication of a foaming or priming boiler 
is usually a "wet stack" and a discernable 
difference in the exhaust sound. Open cyl- 
inder cocks immediately and close throttle 
and discern your water level. 

A07 b) Priming is much the same as foaming; 
you're pulling water into your engine. This 
is especially bad as this tends to wash the 
oil from valves and cylinders and you risk 
possible severe damage to the engine. 
Priming is caused more from carrying too 
high of a water level. It can also occur 
from working steam while ascending and 
descending hills. Again, know the machine 
you are operating, and what safe water 
level you must carry for the terrain you are 
traveling. 

A07 c) Ifan engine starts priming (it will showa wet 
stack), open cylinder cocks, reduce throttle, 
get engine to level area, and discern water 
level. If you can, safely blowdown boiler to 
proper water level. Be sure no bystanders 
are close by for safety. 



S2.14.8 HANDHOLE GASKET BLOWS 
OUT 



A07 



a) Special care should be taken in ensuring A07 
proper installation of handhole gaskets to 
prevent a blowout. 

b) New gaskets need special attention on the A07 
first fire-up. When installing, be sure plate 
surface and mating surface on boiler are 
free of loose scale and debris. Firmly snug 

the gasket after you have properly centered 
the gasket on the handhole, being careful 
not to over tighten as this tends to cut the 
gasket. One of the most common causes 
of handhole gasket blowout is improper 
fitting of gasket to handhole plate. It is very 
important that gasket fits center of handhole 
plate very snug. When steaming up care- 
fully "follow up" your gaskets by making 
sure nut stays snug. Special care must be ex- 
ercised here to make sure you don't rotate 
handhole plate or gasket. Caution should 
be used if boiler has any pressure built up 
on it. The best time to follow up on hand- 
hole gaskets is when steam is almost down 
after your first fire-up. It is important to snug 
them up before boiler cools, because as a 
boiler cools it will form a vacuum, and if 
your handholes are loose, they can suck in 
and drain your boiler. 

c) If a handhole gasket were to blow out: A07 

1 ) Close damper. Prepare to steam down. 
If you have a large fire, you might have 
to kill your fire. This all depends on how 
fast you are losing water and where 
on the boiler the handhole is leaking. 
Under no circumstance should you try 
and continue to operate engine! Peri- 
odic operation of the injector would be 
recommended to keep your water level 
up until you can get your fire down. 

2) Leave engine alone until steam is down. 
Carefully remove handhole plate and 
gasket. Inspect for cause of blowout. 



1 57 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07S2.14.9 TUBE BURST 

Reason: Tubes will deteriorate and corrode over 
time. Usually a pit in the tube surface works its 
way through the tube and a pinhole develops. 
It's rare for a tube to actually "burst," usually 
just a small leak occurs. If the leak occurs on 
firebox end or if leak is a large one, it usually 
puts the fire out. )ust leave the engine on a level 
surface and leave it alone. If the leak is toward 
the smoke box end of the boiler, you will no- 
tice water coming out the smoke box door. 
Again, watch your water level, close damper 
and prepare to steam down, or kill the fire if it 
hasn't done so already. This would depend on 
how fast you're losing water. Don't continue to 
operate the engine. 



A07 S2.1 4.1 LEAKING VALVES 

Several reasons can cause a leaking valve. The 
most common would be a piece of scale or 
debris between valve seat and valve disc/plug. 
Another reason would be a break between 
valve stem and disc/plug (on a globe-type 
valve). Assuming scale on the valve seat, you 
can try opening and closing the valve to try 
and dislodge any debris. If the valve is broken 
or disc/plug has pulled off the end of the valve 
stem, usually there is nothing that can be safely 
done. Unless, you can isolate the valve by shut- 
ting off another valve further up the line. In most 
cases, determine how serious the valve leak is 
and determine if you are losing water and how 
fast, and then decide to either steam down or 
kill the fire. In most cases a normal steam down 
procedure is all that is required. 



A07 S2.1 4.1 1 BROKEN PIPES 

Broken pipes on an engine should not occur if 
engine has been piped with proper materials 
and correct procedures have been followed. 
As previously mentioned in this text, close at- 
tention should be paid to pipe and pipe fittings 
and their condition! However, should a pipe 



or pipe fitting break, carefully try and locate a 
valve up-line and close valve to try and isolate 
the break. Then follow normal steam down 
procedures. If there is no valve up-line that can 
be shut off, ensure safety of yourself and others 
around you by killing the fire immediately. 



S2.14.12 SAFETY VALVE PROBLEMS A07 

As mentioned earlier, testing of this critical 
safety device should be done each time your 
boiler is fired up. This is essential to ensure its 
continued safe operation. In the event your 
safety valve does not open at its preset pressure 
and you have had no success trying to manually 
trip open valve lever, close your damper and 
follow steam down procedure. After closing 
damper, it would be wise to start your injector. 
This will decrease your steam pressure. Under 
no circumstance should the blowdown valve 
be used to release pressure (blowing down will 
lower your water level considerably). Killing 
the fire would not be necessary; providing your 
water level is at a safe level and your steam 
pressure is dropping from running the injector. 
Do not continue to run engine, remove the 
valve and send to a certified shop for repair or 
replace the valve. 



S2.14.13 SAFETY VALVE OPENS BUT WILL A07 
NOT CLOSE 

This problem is more prevalent than valves that 
don't open. There is no immediate danger in a 
safety valve that won't close, as you are only 
losing steam. However, the noise would tend 
to be very annoying! Try to manually open the 
valve a few times under pressure. Hopefully, 
this will seat the valve. Quite often bringing 
your steam pressure down about 25 PSI or so 
will let the valve seat. If after dropping your 
pressure it still does not seat, it obviously has 
an obstruction in the valve or a binding in the 
action of the valve. Follow normal steam down 
procedure. Remove valve and send to a certi- 
fied shop for repairs or replace the valve. 



1 5B 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 S2. 14.14 LEAKING PIPE PLUGS 

More than likely threads were not properly 
cleaned before installation or thread tape/seal- 
ant not properly applied. Under no circum- 
stance should plugs be tightened with boiler 
under pressure! Usually the leak is very small 
and does not mean any immediate danger. Fol- 
low normal steam down procedure. 



A07 S2.1 4.1 5 MELTED GRATES 

a) Closing damper with a hot coal fire. This 
restricts air flow to the grates, although rare 
for a grate to melt from this, it is possible 
to warp or ruin a good set of grates. Grates 
need air flow to keep them cool. Closing 
damper all the way with a hot coal fire 
should only be done in an emergency. 

b) Carrying ashes too high in ash pan is prob- 
ably the biggest reason for melted grates. 
The hot coals in the ash pan touching the 
grates and the restricted air flow is going to 
damage the grates. In some cases a grate bar 
can entirely melt out leaving a huge hole in 
your fire bed and an intense fire burning in 
your ash pan. Follow normal steam down 
procedure. 



) 



1 59 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



The National Board of Boiler and Pressure Vessel Inspectors 
INITIAL BOILER CERTIFICATION REPORT (Form C-1) 




JURISDICTION NO 



MANUFACTURER 



YEAR BUILT 



BOILER TYPE 



ENGINE NO. 



OTHER NO. 



HEATING SURFACE 



OWNER 



OWNER ADDRESS 



OWNER CITY/STATE 



USER 



USER ADDRESS 



USER CITY/STATE 



OPERATOR & LICENSE NO. 




INSIDE DIAMETER 



TUBE SIZE/NUMBER 



TENSILE STRENGTH OF SHELL 



MIN. THICKNESS OF SHELL 



MIN. THICKNESS OF TUBESHEET 



SEAM TYPE 



SEAM EFFICIENCY (from Table S2.10.3) 



MAXIMUM PITCH OF SEAM RIVETS 



JACKET FULLY REMOVED FOR INSP 



MAWP OF BARREL (from Table S2.10.3) 



FIREBOX AND WRAPPER SHEET 



STAYBOLT DIAMETER (Base of Threads) OF THINNEST STAYBOLT 



STAYBOLT PITCH (Max) AT CROWNSHEET 



TYPE OF STAYBOLT (Telltale?) 



MINIMUM THICKNESS OF STAYED SURFACE 



MAWP OF STAYED SURFACES (from Table S2.10.4.1) 



TYPE OF BOTTOM (Ogee, Wet Bottom, etc.) 



CONDITION OF THREADED MOUNTING STUDS 



GRATES, GRATE SUPPORTS, DAMPERS, ASHPAN — SATISFACTORY? 



CLEANED FOR INSPECTION? 



SAFETY EQUIPMENT AND CONTROLS 



SAFETY VALVE (per S2.8.1) 


MANUFACTURER 


SET PRESSURE 


CAPACITY 


SIZE 


FUSIBLE PLUG (per S2.8.4) 


NEW "ASME" PLUG 


OLD PLUG REMOVED F 


OR CROWN INSPECTION? 


FEED METHODS 


INJECTOR(S) BRAND/SIZE 


PUMP 
TYPE 


PREHEATER 
TYPE 


WATER COLUMN 


DRAIN 


WATER LEVEL 
VERIFIED? 


GAGE GLASS (per S2.8.2) 


GUARD 


TYPE 


TRY-COCKS (per S2.8.3) 


NUMBER 


OPERABLE? 


PRESSURE GAGE (per S2.8.5) 


DIAL RANGE 


SIPHON TYPE 



1 6D 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



receives. The history of the equipment shall 
be established, and shall include: date built, 
service history, maintenance, and a review of 
previous inspection records. Process conditions 
shall be reviewed to identify areas most likely 
to be attacked. Surface cleaning procedures and 
requirements shall also be reviewed. 



S4.6.2 



LEAKAGE 



Any leak shall be thoroughly investigated and 
corrective action initiated. Repairs shall be 
in accordance with NBIC Part 3, Repairs and 
Alterations, Supplement 4, Repair and Altera- 
tion of Fiber-Reinforced Thermosetting Plastic 
Pressure Equipment. 



S4.6.3 TOOLS 

The following tools may be required by the 
inspector: 

a) Adequate lighting including overall lighting 
and a portable lamp for close inspections. 

b) Handheld magnifying glass. 

c) Barcol hardness tester. 

d) Small pick or pen knife. 

e) Small quantity of acetone and cotton 
swabs. 



f) Camera with flash capability. 

g) Liquid penetrant testing kit. 



S4.7 



EXTERNAL INSPECTION 



A07 An external inspection is performed to de- 
termine if FRPs are in a condition to operate 
safely. 



S4.7.1 INSULATION OR OTHER 

COVERINGS 

It is not necessary to remove insulation and 
corrosion resistant covers for examination 
of the pressure equipment, if the coverings 
show no sign of mechanical impact, gouging, 
scratching, leaks, etc., and there is no reason 
to suspect any unsafe condition behind them. 
Where insulation coverings are impervious, 
such as a sealed fiberglass jacket, it is recom- 
mended that weep or drain holes be installed at 
the bottom of the insulation jacket as a means 
to detect leakage. 



S4.7.2 



EXPOSED SURFACES 



a) Exposed surfaces of pressure equipment 
are subject to mechanical, thermal, and 
environmental damage. Exposed surfaces 
may show damage from impact, gouging, 
abrasion, scratching, temperature excur- 
sions, etc. Sunlit areas may be degraded 
by ultraviolet light with a resulting change 
in surface color and increased fiber promi- 
nence, but with no loss in physical proper- 
ties. Overheating may also cause a change 
in color. 

b) The location of external damage should be 
noted so that the opposing internal surface 
at that location can be examined. For ex- 
ample, an impact load applied to the outer 
surface may be transmitted through the 
laminate causing a star crack in the inner 
surface. See Figure S4.1 0-t. 

c) Areas that should be closely examined 
are: 

1) Nozzle attachments 

2) Gusset attachments 

3) Flanges 

4) Secondary joints 



1 67 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



5) Hold down lugs 

6) Lifting lugs 

7) Attachments 

S4.7.3 STRUCTURAL ATTACHMENTS 

a) Attachments of legs, saddles, skirts, or other 
components shall be examined for cracks 
where the component attaches to or con- 
tacts the vessel and the component itself. 
See Figure S4.10-r. 

b) Piping loads on nozzles may be excessive. 
Therefore, all nozzles shall be closely 
examined for cracks as shown in Figures 
S4.10-pandS4.10-cc. 



S4.8 



INTERNAL INSPECTION 



An internal inspection is performed to deter- 
mine the condition of internal surfaces and the 
pressure integrity of the item. 



S4.8.1 



GENERAL 



FRP surfaces shall be dry and clean for the in- 
spection. Every effort shall be made to minimize 
damage to the liner during inspection. Defects 
to look for include: 

a) Indentations 

b) Cracks 

c) Porosity 

d) Exposed fibers 

e) Lack of resin 

f) Delaminations 

g) Thinning at points of fluid impingement 



h) Blisters 

i) Scratches 

j) Gouges 

k) Discolorations 

S4.8.2 SPECIFIC AREAS OF CONCERN 

All surfaces shall be examined with both direct 
and oblique illumination. Color differences, 
opacity, stains, wetness, roughness, or any 
deviation from the original surface (original 
cutout sample) condition shall be noted and 
investigated. Liquid level lines shall be defined 
so the laminate condition in both the wet and 
dry zones can be determined. The following 
areas should be closely examined for cracks, 
porosity, or chemical allacks on the liner or 
laminate: 

a) Fittings 

b) Changes in shape 

c) Baffles 

d) Secondary overlays 

e) Nozzles 

f) Cut edges 

g) Supports/internal structures and areas of 
attachment 



S4.9 



INSPECTION FREQUENCY 



Frequency of inspections are established to A07 
determine how often inspections shall be 
performed to ensure safe operation of FRP 
equipment. 



1 68 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



age paths between the flanges and/or 
through the bolt holes. 

2) Insufficient Joint Clamping Force 
Through inadequate design, improper 
assembly, loss of washer/gasket, or 
stress corrosion cracking of connect- 
ing bolts, the clamping force between 
mating flanges is insufficient to retain 
internal pressure. 

3) Washer/Gasket Functional Loss 
Deterioration, caused by corrosion or 
expulsion, provides a path for escaping 
steam and condensate. 



b) 



down by Section VI 1 1 of the ASM E Code and 
the safety factors inherent to the "De-rate 
Curve" calculated by the vessel manufac- 
turer or equally qualified source. Failure 
to maintain operation within the steam 
pressure established by those criteria can, 
in the extreme, lead to cracking. 

Pressure Roll Overload A07 

Included in Yankee Dryer shell design is a 
fatigue factor of safety. Exceeding allow- 
able roll load, in combination with other 
stress-elevating or strength-reducing condi- 
tions, can precipitate fatigue cracking and 
failure. 



4) Flange Machining Variation 

Variations in surface contour of flange 
faces may create leakage paths. 

A07 e) Through-Wall Leakage 

Cast iron inherently exhibits shrinkage 
porosity. Where porosity linkages occur 
between internal and external surfaces, a 
path for steam leakage is made available. 
Such leakage is largely an operational issue, 
as holes are formed in the paper product, 
demanding expedient attention. 



S5.3.2 



CRACKING 



Cracks in cast-iron parts are problematic be- 
cause of the relatively low fracture toughness 
compared with standard, more ductile pressure 
vessel materials and because strengthening 
repair through welding is prohibited. Further- 
more, Yankee dryers are subject to both low- 
and high-cycle fatigue loading. Consequently, 
considerable emphasis is placed upon quality 
inspection for and timely remediation of cracks, 
the central causes of which (in Yankee dryers) 
are: 



S5.3.2.1 THROUGH JOINTS AND 
BOLTED CONNECTIONS 

a) Joint Interface Corrosion 

Jacking forces, which develop from the 
expansion of corrosion products between 
head-to-shell flanges, cause flange separa- 
tion and create leakage paths between the 
flanges and/or through the bolt holes. 

b) Insufficient Joint Clamping Force 
Through inadequate design, improper 
assembly, loss of washer/gasket, or stress 
corrosion cracking of connecting bolts, the 
clamping force between mating flanges is 
insufficient to retain internal pressure. 

c) Washer/Gasket Functional Loss 
Deterioration, caused by corrosion or ex- 
pulsion, provides a path for escaping steam 
and condensate. 

d) Flange Machining Variation 

Variations in surface contour of flange faces 
may create leakage paths. 



A07 a) Overpressurization 

As shell thickness is routinely diminished 
through time, Yankee dryers are designed to 
operate within the pressure limitations set 



S5.3.2.2 THROUGH-WALL LEAKAGE 

Cast iron inherently exhibits shrinkage poros- 
ity. Where porosity linkages occur between 



1 9 1 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



internal and external surfaces, a path for steam 
leakage is made available. Such leakage in the 
shell is largely an operational issue, as holes 
are formed in the paper product, demanding 
expedient attention. 



S5.3.2.3 IMPACT FROM OBJECTS 
PASSING THROUGH THE 
YANKEE/PRESSURE ROLL NIP 

Because of cast iron's low fracture toughness, 
it is especially intolerant of local, high impact 
loads. 



S5.3.2.4 STRESS MAGNIFICATION 
AROUND DRILLED HOLES 

Surface defects, caused by porosity and in- 
dentations, are frequently repaired with driven 
plugs, having some level of interference fit. 
Pumping ports, threaded for a tapered pipe 
fitting, are often installed as a standard Yankee 
design feature for sealant injection into flange 
interfaces. When installed, both produce an 
area of increased stress, local to the hole's 
edge. In the case of driven plugs, this stress 
can be exaggerated by excessive interference 
fits and by closely-grouped or over-lapping 
plugs. Over-torque of threaded, tapered plugs 
can cause cracks to develop at the periphery 
of the hole. 



S5.3.2.5 THERMAL STRESS AND/OR 

MICRO-STRUCTURAL CHANGE 
FROM EXCESSIVE LOCAL 
HEATING AND COOLING 

Transient thermal stresses are usually the high- 
est encountered by a Yankee dryer. Temperature 
differential through and between parts can be 
of such magnitude as to exceed the strength 
of the material. When abnormal thermal loads 
occur, nondestructive examination is crucial 
to ensure the vessel's fitness-for-service. Micro- 
structural change and transient thermal stresses, 



sufficiently high to cause cracking in Yankee 
dryers, have resulted, or could result, from: 

a) bearing failure; 

b) rapid warm-up; 

c.) excessive steam temperature; 

d) heat from fires; 

e) application of water sprays to fight fires and 
remove paper jams; 

f) continuous and excessive local cooling 
from water sprays; 

g) operating heating or cooling systems while 
the Yankee is stationary; e.g., high tem- 
perature air impingement hoods, infra-red 
heating devices, coating showers; 

h) welding and electrical arcs on cast-iron 
parts; and 

i) excessive local temperature due to im- 
proper thermal spray application. 

S5.3.2.6 JOINT INTERFACE CORROSION 

The products of corrosion occupy a larger 
volume than the base metal. The forces cre- 
ated by this expansion are sufficient to cause 
cracking in cast-iron flanges. Without remedia- 
tion, expansion will continue until failure oc- 
curs. Corrosion products form in the presence 
of moisture in the crevice created between 
flanges, wherever the clamping force is insuf- 
ficient to maintain contact between the mating 
surfaces. 



1 92 



NATIONAL BDARD INSPECTION CODE • PART Z 



INSPECTION 



S5.3.2.7 STRESS-CORROSION 

CRACKING OF STRUCTURAL 
BOLTS 

Stress-corrosion cracking (SCC) is the result of 
the combination of a corroding agent, mate- 
rial sensitivity, tensile stress, and temperature. 
At stress levels sufficiently high to induce SCC 
in the presence of a corrosive medium, attack 
proceeds along or through grain boundaries 
perpendicular to the direction of maximum 
tensile stress. Cracking can initiate with little 
or no evidence of general corrosion. 



S5.3.3 



CORROSION 



Corrosion culminates with a failure in compo- 
nent functionality by diminishing load-carrying 
capacity or by generating forces beyond the 
material's strength. In addition to SCC, corro- 
sion-jacking (head to shell joint), wear-corro- 
sion, and deterioration of washers described 
above, oxygen pitting, and general corrosion 
wastage need to be considered as potential 
failure causes. These latter two corrosion condi- 
tions are the result of inadequate boiler water 
treatment. Oxygen pitting has been encoun- 
tered, but rarely. 



S5.4 



INSPECTIONS 



a) Yankee dryers should be inspected on a 
routine-periodic basis. However, as a mini- 
mum, the Yankee dryer should be inspected 
internally and externally at least one time 
every two years. 

b) As appropriate, the following items should 
be included: 

1) head-to-shell joint; 

2) shell out-of-roundness; 

3) shell centcrline thickness; 

4) tilt of head flange; 



5) integrity and security of internal parts; 

6) spigot fit of flanged joints (head-to- 
shell, head-to-journal); 

7) integrity of structural bolts and studs; 
and 

8) previously identified areas of deteriora- 
tion and damage. 

c) When a nonstandard load event occurs, 
or a material non-conformity is noted, an 
inspection should be performed to assess 
fitness for continued service. This inspec- 
tion may involve testing methods not typi- 
cally used in routine inspections and may 
also involve removal of material samples 
for destructive testing. 



S5.5 NONDESTRUCTIVE 

EXAMINATION 

a) Nondestructive examination (NDE) meth- 
ods shall be implemented by individuals 
qualified and experienced with the material 
to be tested using written NDE procedures. 
For Yankee dryers, cast-iron knowledge and 
experience are essential. 

b) Typical nondestructive examination meth- 
ods should be employed to determine 
indication length, depth, and orientation 
(sizing) of discontinuities in Yankee dry- 
ers. Magnetic particle, specifically the wet 
fluorescent method, and dye penetrant 
methods are applicable in the evaluation 
of surface-breaking indications. Ultrasonic 
testing is the standard method for evalua- 
tion of surface-breaking and embedded in- 
dications. Radiographic methods are useful 
in the evaluation of embedded indications. 
Acoustic Emission Testing can be used to 
locate and determine if a linear indication 
is active, i.e., propagating crack. Metallo- 
graphic analysis is useful in differentiating 
between original casting discontinuities 
and cracks. 



1 93 



NATIONAL BOARD INSPECTION CDDE • PART 2 — INSPECTION 



c) When nondestructive testing produces an 
indication, the indication is subject to inter- 
pretation as false, relevant, or non-relevant. 
If it has been interpreted as relevant, the 
necessary subsequent evaluation will result 
in a decision to accept, repair, replace, 
monitor, or adjust the maximum allowable 
operating parameters. 



A07 S5.6 



PRESSURE TESTING 



Water pressure testing in the field is not rec- 
ommended because of the large size of the 
Yankee dryers and the resulting combined 
weight of the Yankee dryer and the water 
used in testing. This combined weight can 
lead to support structure overload. Several 
failures of Yankee dryers have occurred 
during field pressure testing using water. If 
this test must occur, the following review 
is recommended: 



contact the Yankee dryer shell at each 
end near the head-to-shell joint. The 
manufacturer can provide information 
on saddle sizing and location so that 
the Yankee dryer is properly supported 
for the test. 

b) When pressure testing is desired to evaluate 
forms of deterioration, acoustic emission 
testing, with steam or air, is recommended. 
Typically, the test pressure used is the op- 
erating pressure. 



3) 



The testing area should be evaluated for 
maximum allowable loading, assum- 
ing the weight of the Yankee dryer, the 
weight of the water filling the Yankee 
dryer, and the weight of the support 
structure used to hold the Yankee dryer 
during the test. 

The manufacturer should be contacted 
to provide information on building 
the Yankee dryer support structure for 
the water pressure test. Typically, the 
Yankee dryer is supported on saddles 
that contact the testing area and should 
be evaluated for maximum allowable 
loading, assuming the weight of the 
Yankee dryer, the weight of the water 
filling the Yankee dryer, and the weight 
of the support structure used to hold the 
Yankee dryer during the test. 

The manufacturer should be contacted 
to provide information on building the 
Yankee dryer support structure for the 
water pressure test. Typically, the Yan- 
kee dryer is supported on saddles that 



1 94 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



SUPPLEMENT 6 

CONTINUED SERVICE AND 
INSPECTION OF DOT 
TRANSPORT TANKS 



S6.3 



ADMINISTRATION 



S6.1 



SCOPE 



This supplement provides rules for contin- 
ued service inspections of transport tanks, 
i.e., cargo tanks, rail tanks, portable tanks, 
and Ton Tanks that transport dangerous 
goods as required in the Code of Federal 
Regulations, Title 49, Parts 100 through 
185, and the United Nations Recommen- 
dations forTransport of Dangerous Goods- 
Model Regulations. This supplement, where 
applicable, shall be used in conjunction 
with other applicable Parts of the National 
Board Inspection Code (NBIC) and Section 
XII, TransportTanks, of the ASM E Boiler and 
Pressure Vessel Code. 



S6.2 



TERMINOLOGY 



a) The terminology used in this supplement, 
in some cases may be in conflict with 
terms and definitions normally used in the 
repair and alteration of pressure-retaining 
items. Considering these differences, this 
supplement in the Definition Section has 
incorporated definitions and terms speci- 
fied in CFR 49, Parts 1 00 through 1 85. 

b) When conflicts are identified between this 
part and the regulations of the Competent 
Authority regarding the examination, in- 
spection, testing, repair, and maintenance 
for the continued qualification of transport 
tanks, the regulations of the Competent 
Authority take precedence. 

c) Rules for repairs and modifications of trans- 
port tanks are provided in Part 3, Repairs 
and Alterations, Supplement 6. 



b) 



The Competent Authority's requirements 
describe the frequency, scope, type of in- 
spection (internal, external, or both), type 
of examination (nondestructive, spark test, 
etc.), and the documentation requirements 
for the inspection. 

For transport tanks under the Jurisdiction 
of the Department of Transportation, the 
Registered Inspector shall have a thorough 
knowledge of the Code of Federal Regula- 
tions, Title 49, Parts 100 through 185. 



S6.4 



INSPECTION 



This section will establish the appropriate meth- A07 
ods to be used for continued service inspec- 
tions. Inspections for repairs and modifications 
of transport tanks is located in Part 3, Repairs 
and Alterations, Supplement 6. 



S6.4.1 



SCOPE 



This section describes the duties, qualifications, 
and responsibilities of the Registered Inspector, 
and the scope of inspection activities permitted. 



S6.4.2 GENERAL REQUIREMENTS FOR 

INSPECTORS 



A07 



a) The Inspector shall be a National Board rec- 
ognized Inspector, i.e., Authorized Inspec- 
tor (Al), Qualified Inspector (Ql), Certified 
Individual (CI), or a Registered Inspector 
(Rl). The Registered Inspector is a position 
established by CFR 49 Parts 100 through 
1 85 for Continued Service Inspections. This 
individual's duties and responsibilities are 
subject to DOT and not QAI-1 . 

b) For continued service inspections, the 
owner-user's Registered Inspector can be 



1 95 



NATIONAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



used to perform inspections and testing 
in accordance with the Code of Federal 
Regulations, Title 49, Parts 100 through 
185, Transportation. 



S6.4.5 



CODES OF CONSTRUCTION 



A07 S6.4.3 



REGISTRATION OF INSPECTORS 



Fach Registered Inspector performing duties 
and responsibilities for continued service in- 
spections or inspections for repairs and modi- 
fications as specified in this section and 49 CFR 
Part 180 is required to meet the qualification 
requirements of S6.4.4 , S6.4.6 and S6.4.7, as 
applicable to be registered with DOT. 



A07 S6.4.4 



QUALIFICATIONS OF 
INSPECTORS 



a) Registered Inspector (Rb means a person 
registered with the US Department of 
Transportation (DOT) in accordance with 
Subpart F of Part 107 of 49 CFR who has 
the knowledge and ability to determine 
whether a cargo tank conforms to the ap- 
plicable DOT specification. A Registered 
Inspector may or may not be an employee 
of the approved facility. In addition, Regis- 
tered Inspector means a person who meets, 
at a minimum, any one of the following: 

1) Has an engineering degree and one 
year of work experience. 

2) Has an associate degree in engineering 
and two years of work experience. 

3) Has a high school diploma or GED and 
three years of work experience. 

4) Has at least three years experience in 
performing the duties of a Registered In- 
spector by September 1 , 1 991 , and was 
registered with the DOT by December 
31,1995. 



a) The Registered Inspector is responsible A07 
to ensure that all repairs or modifications 
(including re-rating) are performed in ac- 
cordance with the original code of con- 
struction of the Transport Tank. 

b) For repairs or modifications, the original A07 
code of construction for DOT vessels shall 

be either ASME Section VIII Division I or 
Section XII. 



S6.4.6 INSPECTOR DUTIES FOR 

CONTINUED SERVICE 
INSPECTIONS 



A07 



a) Inspectors performing Continued Service 
Inspections required by the Code of Federal 
Regulations (CFR), Title 49, Part 1 80 shall be 
a Registered Inspector. The Inspector shall 
satisfy the following requirements: 

1) Has satisfied DOT requirements as a 
Registered Inspector. 

2) Has successfully completed the Na- 
tional Board's Web-based training 
program for Registered Inspectors and 
been issued a National Board certificate 
of completion. 

3) Has received authorization from DOT 
as a Registered Inspector. 

4) Has been registered by DOT for the 
Classification(s) of Transport Tanks to 
be inspected. 

b) Inspectors performing Continued Service A07 
Inspections meeting the requirements of 
S6.13 (Cargo Tanks), S6.1 4 (Portable Tanks), 

or S6.1 5 (Ton Tanks), and 49 CFR, Part 1 80 
shall perform all inspections and tests re- 
quired by this section and any additional 



1 96 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07 requirements, as applicable in 49CFR Part 
180. The Inspections and Tests shall be 
documented as follows: 

1) All inspections and tests shall be con- 
ducted, as applicable, in accordance 
withS6.13, S6.14,andS6.15. 

2) All inspections and tests shall be 
documented in an Inspection Report 
as required by S6.5. 

3) All inspection and test reports shall be 
maintained by the Owner-User or Ship- 
per of the transport tank in accordance 
with S6.5. 



the following requirements for Periodic 
Inspection andTest Frequencies in S6.13 
are properly satisfied as specified by: 

a. Periodic Inspection and Test frequen- 
cies: Table S6.13 

b. Pressure Test Requirements for Cargo 
Tank by specification: Table S6.1 3.6 

b) Additional criteria for material thickness A07 
requirements for a cargo tank specification 
are listed, as applicable for material type 
(ferrous and non ferrous) in various tables 
in S6.13. 



4) All inspection and test reports shall be 
available for review by an authorized 
representative of the Department of 
Transportation. 

A07 c) The requirements for inspections are pro- 
vided for each classification of transport 
tanks as specified in S6.4.6.1, cargo tanks, 
S6.4.6.2, portable tanks and S6.4.6.3, ton 
tanks. 



A07 S6.4.6.1 INSPECTOR DUTIES FOR 
CONTINUED SERVICE 
INSPECTION OF CARGO TANKS 

a) Cargo tanks constructed in accordance 
with a DOT Specification that are required 
to be tested or inspected can not be used 
for transportation until the required test 
or inspection has been successfully com- 
pleted. 

1) The Registered Inspector shall inspect 
cargo tanks in accordance with S6.13, 
and in conjunction with the require- 
ments of 49CFR Parts! 80.401 through 
180.417. 



S6.4.6.2 INSPECTOR DUTIES FOR A07 

CONTINUED SERVICE 
INSPECTION OF PORTABLE 

TANKS 

a) Portable Tanks constructed in accordance A07 
with DOT, United Nations (UN), or Inter 
Modal (IM) specifications that are required 

to be tested or inspected cannot be used 
for transportation until the required test or 
inspections have been successfully com- 
pleted. 

b) The Registered Inspector shall inspect A07 
portable tanks in accordance with S6.14, 

in conjunction with the requirements of 
49CFR, Parts 180.601 to 180.605. 

c) The Registered Inspector in the performance A07 
of theirduties shall ensure that the following 
requirements for Inspection Intervals and 
Pressure Test Requirements in S6.14 are 
properly satisfied as specified by: 

1) Inspection Intervals: Table S6. 14 

2) Pressure Testing Requirements: Table 
S6.14.6 



The Registered Inspector in the perfor- 
mance of their duties shall ensure that 



1 97 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 S6.4.6.3 INSPECTOR DUTIES FOR 
CONTINUED SERVICE 
INSPECTIONS OF TON TANKS 

A07 a) Ton Tanks constructed in accordance with 
DOT 106A or DOT 1 1 OA requirements 
that are required to be tested and inspected 
cannot be used for transportation until 
the required test and inspection has been 
made. 

A07 b) The Registered Inspector shall inspect ton 
tanks in accordance with S6.15, in con- 
junction with the requirements of 49CFR, 
Part 180.519. 

A07 c) The Registered Inspector in the performance 
of his or her duties shall ensure that the re- 
quirements for Ton Tank Periodic Inspection 
and Test Frequencies in Table S6.1 53 are 
properly satisfied. 

A07 d) Additional criteria for material thickness, 
safety valve, and acceptable material with 
acceptable tensile strength and elongation 
requirements for ton tanks are listed in the 
following tables of S6.1 5: 

1) Thickness of Plate and Safety Valve 
Requirements: Table S6. 15.1 -a 

2) Acceptable Materials with Acceptable 
Tensile Strength and Elongation Re- 
quirements: Table S6.1 5.1 -b 



A07 S6.4.7 CONTINUED SERVICE, 

INSPECTION FOR DOT 
TRANSPORT TANKS SCOPE 

This supplement details frequencies of testing 
requirements, type of tests required, acceptance 
criteria, and inspection reports of transport 
tanks. 



A07 S6.4.7.1 ADMINISTRATION 

The Competent Authority's requirements de- 
scribe the frequency, scope, type of inspec- 



tion, and documentation requirements for the 
inspection and are noted in the US Code of 
Federal Regulations, Title 49 CFR, Parts 100 
through 185. 



S6.4.7.2 INSPECTION AND TEST 

REQUIRED FREQUENCIES 



A07 



Inspection and frequencies for periodic test- 
ing of cargo tanks are found in S6.13; portable 
tanks S6.14; and ton tanks S6.15. 



S6.4.7.3 EXTERNAL VISUAL AND 
PRESSURE TESTS 



A07 



External visual inspection tests shall be per- 
formed in accordance with S6.13.1 for cargo 
tanks; S6.14.5 for portable tanks; and S6.15.2 
for ton tanks. The pressure tests for cargo tanks 
shall be as specified in S6.13.6; S6.14.6 for 
portable tanks; and S6.1 5.3 for ton tanks. 



S6.4.7.4 LEAK TIGHTNESS TESTING OF 
TRANSPORT TANKS 



A07 



S6.4.7.4.1 CARGO TANKS 

a) Each cargo tank must be tested for leaks A07 
in accordance with Table S6.13, Periodic 
Inspections and Test, and per the require- 
ments in S6.13.9. The minimum leakage 
test pressure of 80% of MAWP may be 
accepted by provisions of the Competent 
Authority (see 49CFR1 80.407[h]). 

b) All external and accessible portions of A07 
piping up to the first closure when offered 

for transportation shall be tested for leak 
tightness. 

1) All closure fittings must be in place A07 
during the leak tightness test. 

2) The leak tightness test pressure must be A07 
maintained for at least 5 minutes. 



1 98 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



A07 3) All sources of leakage must bo properly 
repaired. 

A07 4) A cargo tank that fails to retain leakage 
test pressure may not be returned to 
service as a specification cargo tank. 



A07 S6.4.7.4.2 PORTABLE TANKS 

Fach portable tank piping must be tested for 
leaks in accordance with the inspection inter- 
vals in Table S6.14 and per the procedures in 
S6.14.6. 

a) The minimum leakage test pressure is as 
specified in Table S6.1 4.6. 

b) All closure fittings must be in place during 
the leak tightness test. 

c) The test pressure must be maintained for at 
least 5 minutes. 

d) All sources of leakage must be properly 
repaired. 

e) A portable tank that fails to retain leakage 
test pressure may not be returned to service 
as a specification portable tank. 



A07 S6.4.7.4.3 TON TANKS 

Each ton tank shall be tested at intervals speci- 
fied in Table S6. 15.3, by procedure at pressures 
specified for the classification of the tank. 



A07 S6.4.7.4.4 LEAK TIGHTNESS TESTSNG OF 

VALVES 



A07 S6.4.7.4.4.1 CARGO TANKS 

Cargo tank valves shall be periodically visually 
inspected in accordance with the applicable 
provisions in S6. 13.2(e) and leak tested at 
time intervals specified inTable S6.1 3.This test 



should coincide with the leak test for piping as 
specified in S6.4.7.4.1 and shall include: 

a) All valves under pressure shall be leak A07 
tested at the pressure specified, for leak- 
age through the valve, and externally (e.g., 
valve bonnet). 

b) During the inspection a suitable method A07 
must be used for detecting the existence 

of leaks. This method must consist either of 
coating the entire surface of all joints under 
pressure with a solution of soap and water, 
or using other equally sensitive methods. 

c) All emergency devices and valves includ- A07 
ing self-closing stop valves, excess flow 
valves and remote closure devices must 

be free from corrosion, distortion, erosion, 
and external damage that will prevent safe 
operation. Remote closure devices and self 
closing stop valves must be functioned to 
demonstrate proper operation. 



S6.4.7.4.4.2 PORTABLE TANKS 

Portable tank valves shall be periodically visu- A07 
ally inspected in accordance with the appli- 
cable provisions of S6.14.3 and leak tested at 
time intervals specified in S6.14. Leak tightness 
testing requirements are as specified in Table 
S6.14.6 and shall include: 

a) Piping, valves, and gaskets must be free A07 
from corroded areas, defects, and other 
conditions, including leakage, that might 
render the portable tank unsafe for filling, 
discharge, or transportation. 

b) All emergency valves shall be free from A07 
corrosion, distortion, and any damage or 
defect that could prevent their normal op- 
eration. 

c) Remote closure devices and self-closing A07 
stop valves must be functioned to demon- 
strate proper operation. 



1 99 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



A07 d) For testing of internal self-closing stop valves 
see Appendix A and B of 49CFR1 80. 

A07 e) The intermediate periodic inspection and 
test shall include an internal and external 
inspection, unless exempted, and an ex- 
ternal inspection of the portable tank and 
fittings, leakage test, and test for satisfactory 
operation of all service equipment. 



A07 S6.4.7.4.4.3 TON TANKS 

Ton tanks valves shall be periodically visually 
inspected in accordance with the applicable 
provisions of S6.15.2 and leak tested in ac- 
cordance with the provisions of S6.15.3 and 
S6, I 5.3.1. This test should coincide with the 
tank retest intervals as stipulated in Table 
S6.15.3. 



A07 S6.4.7.5 LEAK TIGHTNESS TESTING OF 
SAFETY RELIEF DEVICES 



A07 S6.4.7.5.1 CARGO TANKS 

a) All re-closing pressure relief devices for 
cargo tanks shall be visually inspected 
per S6.1 3.2(e) and pressure tested for leak 
tightness as stipulated in S6. 13.6(b) at fre- 
quencies specified in Table S6.1 3. 

Note: when performing this test, all re- 
closing pressure relief valves, including 
emergency relief vents, and normal vents 
shall be removed for inspection and tested 
as follows: 

A07 b) Leakage test for any venting device re- 
quired for the interval specified in Table 
S6.13 must include testing the device in 
place, except that any venting device set to 
discharge at less than the leakage pressure 
must be removed or rendered inoperative 
during the test. 



Non re-closing relief device discs should A07 
be evaluated for replacement at the time 
of the pressure test intervals. 



A07 



S6.4.7.5.2 PORTABLE TANKS 

Portable tanks subject to a five-year periodic 
inspection and leak tightness test, except for 
DOT Specification 56 and 57 Portable Tanks, 
shall include: 



a) All re-closing pressure relief devices must A07 
be removed from the tank and tested 
separately unless they can be tested while 
installed on the portable tank. 

b) If a leakage test is specified being less than A07 
the MAVVP, the re-closing pressure relief 
valves can be tested in place. 

c) Visual inspection shall include all emer- A07 
gency devices to ensure that they are free 
from corrosion, distortion, and any damage 

or defects that could prevent the devices 
from operating as designed. 

d) For Specification 57 Portable Tanks, during A07 
the air test, the pressure relief device may be 
removed or left in place. If the relief device 

is left in place during the test, the device's 
discharge opening shall be plugged. (See 
Special Requirements for testing of pressure 
relief devices for Specifications 51 and 56 
Portable Tanks in S6. 14. 6.2.) 

e) For Specification 60 PortableTanks, re-clos- A07 
ing pressure relief devices may be removed 
from the tank and tested separately unless 
they can be tested while installed in the 
portable tank. 

f) If portable tanks are fitted with non-reclos- A07 
ing relieving devices, consideration for 
replacing the discs for these devices should 

be evaluated at the time of the leak tightness 
test interval. 



2QD 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



S6.4.7.5.3 TON TANKS 

A07 Fach ton tank designed to be removed from 
tank cars for filling and emptying shall have 
their safety relief devices, if fitted, tested and 
subjected to a periodic inspection and test at 
frequencies established in Table S6.1 5.3. 

A07 a) All pressure relief devices shall be retested 
by air or gas for the start-to-discharge and 
vapor tightness requirements. 

A07 b) For ton tanks fitted with rupture discs and 
fusible plugs, the inspection of these de- 
vices and disposition must be as described 
in S6.15.3.3. 



A07 S6.4.7.6 TESTING OF MISCELLANEOUS 
PRESSURE PARTS 



A07 S6.4.7.6.1 CARGO TANKS 

Cargo tanks provided with manholes (or hand- 
holes) shall be inspected in accordance with 
S6.13.2 and all major structural attachments 
as defined in CFR1 80.407(d)(2)(viii), including 
the upper coupler (fifth wheel) assembly and 
ring stiffeners shall be inspected in accordance 
with S6.1 3.3. Other miscellaneous items shall 
comply with the following: 

A07 a) Cargo tanks equipped with linings that 
protect the cargo tank from the commod- 
ity being transported shall be inspected, 
unless exempted, in accordance with the 
provisions of S6.13.5. 

A07 b) For cargo tanks equipped with a heating 
system, the heating system shall be pressure 
tested as required by S6.1 3.6.4. 

A07 c) Delivery hoses for MC330 and MC331 
cargo tanks shall be leak tightness tested. 
Any conditions as noted in S6.1 3.9, which 
exist for the delivery hose, shall be unac- 
ceptable and prevent its continued use. 



d) New or replaced delivery hose assem- A07 
blies shall meet all of the requirements of 
S6. 13.10. In addition to this requirement, 
for commodities transported in MC330 and 
MC331, the delivery hose assemblies may 
be installed or carried on the cargo lank. 
The operator is required to perform inspec- 
tions as required in 49CFR1 80.41 6. 



S6.4.7.6.2 PORTABLE TANK A07 

For portable tanks, the periodic visual inspec- 
tion shall include: 

a) The operation of tightening devices for A07 
manhole and handhole covers, or the gas- 
kets are operative and there is no leakage 

at the manhole or handhole cover or gasket 
at leakage pressure. 

b) The framework structural supports and the A07 
lifting device located on the portable tank 
shall be in satisfactory condition. 



S6.4.7.6.3 TON TANKS A07 

Visual inspection of ton tanks shall include dam- 
aged chimes or protective rings if so fitted. 



S6.4.7.7 ACCEPTANCE CRITERIA A07 

All defects or deficiencies discovered during the 
inspection process of a transport tank shall be 
documented in the Inspection Report and dis- 
cussed with the owner or user of the transport 
tank at the time of the inspection. Defects or 
deficiencies shall be corrected using appropri- 
ate methods, and tested prior to returning the 
transport tank to service. (See S6.1 0.) 



ZD 1 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



A07 S6.4.7.8 INSPECTION REPORT 



S6.5.2 



STAMPING 



A07 S6.4.7.8.1 CARGO TANKS 

Cargo tank Inspection Reports, as a minimum, 
shall include the information specified in 
S6. 13.6.7 and S6.13.8 (as applicable) and 
49CFR180.417. 



A07 S6.4.7.8.2 PORTABLE TANKS 

Portable tank Inspection Reports shall satisfy the 
requirements of S6.1 4.9 in addition to those of 
49CFR Part 180.605. 



A07 S6.4.7.8.3 TON TANKS 



a) Transport tanks represented as manufac- 
tured to a DOT specification or a United 
Nation's (UN) standard shall be marked 
on a non-removable component of the 
transport tank with specification markings 
conforming to the applicable specification. 
The specification marking is required to be 
located in an unobstructed area with letters 
and numerals identifying the standard or 
specification. Unless otherwise specified by 
Part 1 78.3 of the Code of Federal Regula- 
tions, the markings must identify the name 
and address or symbol of the transport 
tank manufacturer or, where specifically 
authorized, the symbol of the approval 
agency certifying compliance with a UN 
standard. 



Ton tank Inspection Reports shall satisfy the 
requirements of S6.1 5.3.6 in addition to those 
of 49CFR Part 180.51 9: 



S6.5 STAMPING AND RECORD 

REQUIREMENTS FOR DOT 
TRANSPORT TANKS IN 
CONTINUED SERVICE 

This section provides for preparation, distribu- 
tion and maintenance of inspection records and 
stamping requirements for Continued Service 
Inspections of Transport Tanks, i.e., cargo tanks, 
portable tanks, and ton tanks. 



S6.5.1 



GENERAL 



To ensure that transport tanks can maintain their 
authorization to transport hazardous materi- 
als by the mode of transport permitted by the 
Competent Authority (DOT), the specification 
transport tank's owner or user shall satisfy, 
as applicable, that the records and stamping 
requirements of this supplement and Code of 
Federal Regulations, Title 49, Part 1 80 (49 CFR 
180) have been satisfied. 



b) Symbols required by the Department of 
Transportation (DOT) must be with the ap- 
proval of the DOT Associate Administrator. 
Duplicative symbols are not authorized. 
Stamping and symbol requirements for 
transport tanks that are under different rules 
than CFR 49, Parts 100 through 185 shall 
comply with the applicable Competent 
Authorities rules and regulations. 

c) The detailed markings, i.e., stamped, em- 
bossed, burned, printed, etc., size of the 
markings, capacities, etc., are specified in 
Part 1 78.3 of the Code of Federal Regula- 
tions, Title 49, as follows: 

1 ) ASME-Stamped Transport Tanks 

a. Transport tanks stamped with the 
ASME Section XII Code Symbol 
shall satisfy the applicable require- 
ments of that Code. Transport tanks 
manufactured prior to the adoption 
of ASME Section XII by the Compe- 
tent Authority were manufactured 
in accordance with ASME Section 
VIII, Div. 1. Stamping with the 
ASME Section VIII, Div. 1 "U"Code 



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INSPECTION 



Symbol Stamp is dependant on 
pressure and/or media limitations. 

b. When the stamping on a transport 
tank becomes indistinct or the 
nameplate is lost or illegible, but 
traceability to the original transport 
tank is still possible. To satisfy this 
requirement, as a minimum, origi- 
nal source data from the manufac- 
turer of the vessel or records in pos- 
session of the tank owner should 
be used to establish traceablity to 
the stamping with the concurrence 
of the Inspector, and approval of 
the Competent Authority, and if re- 
quired the Jurisdiction. The Inspec- 
tor shall instruct the owner or user 
to have the stamped data replaced. 
All re-stamping shall be done in 
accordance with the original code 
of construction (ASME Section XII, 
or ASME Section VIM, Div. 1, as ap- 
plicable). Request for permission to 
re-stamp or replace the nameplate 
shall be made to the Competent 
Authority and, if required, the Juris- 
diction. Application must be made 
on the Replacement of Stamped 
Data Form, NB-136 (See 5.5.2). 
Proof of the stamping and other 
such data, as is available, shall be 
furnished with the request. When 
traceability cannot be established, 
the Competent Authority shall be 
contacted. 

2) Re-stamping or replacement of name- 
plates 

Re-stamping or replacement of the 
nameplate as authorized by the Com- 
petent Authority shall only be done in 
the presence of the Inspector, i.e., AI, 
Ql, CI, or National Board Commis- 
sioned Inspector, as required by ASME 
Section XII and the applicable Modal 
Appendix, or as required by the Com- 
petent Authority. For transport tanks 



manufactured to ASME Section VIII, 
Division 1, re-stamping or replacement 
shall only by done in the presence of 
an Authorized Inspector or a National 
Board Commissioned Inspector. 



S6.5.3 OWNER OR USER REQUIRED A07 

RECORDS FOR CARGO TANKS 

a) Each Owner or User of a DOT Specifica- 
tion cargo tank shall retain the appropriate 
ASME Manufacturer's Data Report, Form 
T-1, for Section XII Transport Tanks or Form 
U-1A for Section VIII, Division 1 Pressure 
Vessels, and related papers certifying that 
the DOT Specification cargo tank identified 
in the documents was manufactured and 
tested in accordance with the applicable 
tank specification. 

1) In addition to the appropriate ASME 
Manufacturer's Data Report, the re- 
quired documents shall include any 
certification of emergency discharge 
control systems required by 49 CFR 
1 73.31 5(n) or 49 CFR 1 80.405(m). 

a. The Certificate of Compliance is- 
sued by the cargo tank motor ve- 
hicle manufacturer (CTMVM) and 
all preceding certificates issued by 
preceding manufacturers signed 
and dated by a Registered Inspec- 
tor or Company Official or Design 
Certifying Engineer as required by 
49 CFR 178.337-1 8(a)(1) or (a)(2) 
as appropriate. The certificate must 
contain a statement indicating 
whether or not the cargo tank was 
postwcld heat treated for anhydrous 
ammonia service as specified in 49 
CFR 178.337-1 (f); 

b. Cargo tank fabrication drawings; 

c. Piping drawing that identifies the 
location, make, model, and size of 



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NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



each valve and the arrangement of 
all piping associated with the cargo 
tank motor vehicle; 

d. Assembly drawing; 

e. Pressure test report for the piping, 
valves and fittings; 

f. Hose certification; and 

g. Certification of emergency dis- 
charge control systems. 

2) The documents required by 49 CFR 
shall be retained throughout ownership 
of the cargo tank and for one year after 
relinquishing ownership. 

3) In the event of a change in ownership, 
the prior owner shall retain non-fading 
photocopies of these documents for 
one year. 

4) Users of a cargo tank that are not the 
Owner shall retain a copy of the vehicle 
certification report as long as the cargo 
tank motor vehicle is used by the User 
and for one year thereafter. 

5) The required documents specified in 
this Section shall be maintained at the 
Owner or Users principal place of busi- 
ness, or at a location where the cargo 
tank is housed or maintained. 

6) Items (4) and (5) do not apply if the User 
leases the cargo tank for less than 30 
days. 

b) For DOT Specification cargo tanks that 
were manufactured prior to September 1, 
1 995, that were not constructed to ASME 
Section VIII, Division 1 (Non Code Pressure 
Vessels), but wishes to certify the cargo tank 
to a DOT Specification Cargo Tank, the fol- 
lowing shall be complied with: 

1 ) The Owner shall perform the appropri- 
ate tests and inspections as required 



by 49 CFR Part 178 under the direct 
supervision of a Registered Inspector to 
determine if the cargo tank conforms to 
the applicable specification. 

2) Both the Owner and the Registered 
Inspector shall certify that the cargo 
tank fully conforms to the applicable 
specification. 

3) The Owner shall maintain the certifica- 
tion as specified in this section. 

For ASME -stamped cargo tanks, the Owner 
must have the manufacturer's certification 
and the appropriate ASME Manufacturer's 
Data Report on file. 

1 ) If the Owner does not have the manu- 
facturer's certification and the appropri- 
ate ASME Manufacturer's Data Report, 
the following shall be satisfied: 

a. If the pressure vessel of the cargo 
tank is registered with the National 
Board of Boiler and Pressure Vessel 
Inspectors (National Board), they 
shall obtain a copy of the Manu- 
facturer's Data Report from the 
National Board. 

b. If the pressure vessel of the cargo 
tank is not registered with the 
National Board, they shall copy 
the cargo tank's identification and 
ASME Code nameplate information 
and retain this information in their 
files. 

2) If the nameplate information is copied 
as identified in (c)(1 )b., the Owner and 
the Registered Inspector shall certify 
that the pressure vessel of the cargo 
tank fully conforms to the DOT speci- 
fication. 

3) The Owner shall retain all certification 
documents in accordance with reten- 
tion periods specified in this supple- 
ment. 



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NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



A07 S6.5.3.1 REPORTING REQUIREMENTS BY 
THE OWNER OR USER OF TESTS 
AND INSPECTIONS OF DOT 
SPECIFICATION CARGO TANKS 

The Owner or User that performs the required 
Test and the Registered Inspector that performs 
the inspection as specified at frequencies es- 
tablished in Table S6. 13 shall prepare a written 
report in English that satisfies the requirements 
of. S6.13. Each test and inspection facility that 
fails a cargo tank based on a test or inspection 
report shall notify the owner, register the report 
with the National Board, and provide a copy 
of the test report indicating the failure to the 
competent authority. 



A07 S6.5.3.2 DOT MARKING REQUIREMENTS 
FOR TEST AND INSPECTIONS 
OF DOT SPECIFICATION 
CARGO TANKS 

Each cargo tank that has successfully completed 
the test and inspection contained in S6.1 3 shall 
be durably and legibly marked, in English. The 
markings shall comply with the following: 

a) Date (month and year) of the type of test 
or inspection performed, subject to the fol- 
lowing: 

1) date shall be readily identifiable with 
the applicable test or inspection; 

2) markings shall be 32mm (1.25 in.) 
high, near the specification plate or 
anywhere on the front head of the cargo 
tank. 

b) The type of test or inspection may be ab- 
breviated as follows: 

1) "V" for external visual inspection; 

2) "I" for internal visual inspection; 

3) "?" for pressure test; 

4) "L" for lining inspection; 



5) "T" for thickness inspection; 

6) "K" for leakage test for a cargo tank 
tested to the requirements of S6.13.9, 
except for cargo tanks subject to the 
requirements of S6. 13.9 (d)(10); and 

7) "K-EPA27" for a cargo tank tested to the 
requirements of S6.1 3.9(d)(1 0)that was 
manufactured after October I, 2004. 

c) For a cargo tank motor vehicle composed 
of multiple cargo tanks constructed to the 
same specification, which are tested and 
inspected at the same time, one set of test 
and inspection markings may be used to 
satisfy the requirements of S6.5.3.2. 

d) For a cargo tank motor vehicle composed 
of multiple cargo tanks constructed to dif- 
ferent specifications, which are tested and 
inspected at different intervals, the test and 
inspection markings shall appear in the 
order of the cargo tank's corresponding 
location, from front to rear. 



S6.5.4 OWNER OR USER REQUIRED 
RECORDS FOR PORTABLE 

TANKS 



A07 



a) The Owner of each portable tank or their 
authorized agent shall retain a written re- 
cord of the date and results of all required 
inspections and tests, including the ASME 
Manufacturer's Data Report. 

b) The written record, if applicable, shall in- 
dicate the name and address of the person 
that performed the inspection or test. The 
inspection and test shall comply with the 
requirements of the portable tank's speci- 
fication, as provided in 49 CFR, Part 1 78. 

c) The Owner shall maintain a copy of the 
ASME Manufacturer's Data Report. He shall 
also maintain a certificate(s) that is signed 
by the manufacturer of the portable tank, 
and by the authorized design approval 



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NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



agency, as applicable indicating compli- 
ance with the applicable portable tank 
specification. 

d) The signed certificate, including the ASME 
Manufacturer's Data Report shall be main- 
tained by the Owner or their authorized 
agent during the time that the portable tank 
is used for service. DOT Specifications 56 
and 57 portable tanks are exempt from this 
requirement. 



c) When required, the date (month and year) 
of the last visual inspection; 

d) Markings shall be placed on or near the 
metal identification plate; and 

e) Markings shall be 3mm (0.118 in.) high 
when on the metal identification plate and 
1 2 mm (0.47 in.) high when on the portable 
tank. 



A07 S6.5.4.1 REPORTING OF PERIODIC AND 
INTERMEDIATE PERIODIC 
INSPECTION AND TESTS OF 
DOT SPECIFICATION PORTABLE 

TANKS 

a) The user of portable tanks shall satisfy the 
requirements for Periodic and Intermediate 
Periodic Inspection and Tests of portable 
tanks as specified in Table S6.14 of this 
Supplement and shall maintain the results 
of these tests as required in S6.5.4. 

b) The methods and procedures to be used in 
the performance of the required Periodic 
and Intermediate Inspections and Tests are 
specified in S6.14. 



A07 S6.5.4.2 MARKING REQUIREMENTS FOR 
PERIODIC AND INTERMEDIATE 
INSPECTION AND TEST FOR IM 
OR UN PORTABLE TANKS 

Each IM or UN portable tank that has success- 
fully completed the required Periodic or Inter- 
mediate Inspection and Test shall be durably 
and legibly marked, in Fnglish. The markings 
shall comply with the following: 

a) Date (month and year) of the last pressure 
test; 

b) Identification markings of the approval 
agency witnessing the test; 



S6.5.4.3 DOT MARKING REQUIREMENTS A07 
FOR PERIODIC AND 
INTERMEDIATE INSPECTION 
ANDTESTSOFDOT 
SPECIFICATION 51, 56, 57, OR 
60 PORTABLE TANKS 

Each DOT Specification 51 , 56, 57, or 60 por- 
table tank that has successfully completed the 
required Periodic or Intermediate Inspection 
and Test shall be durably and legibly marked, 
in English. The markings shall comply with the 
following: 

a) Date (month and year) of the most recent 
test; 

b) Markings shall be placed on or near the 
metal certification plate; 

c) Markings shall be accordance with 49 CFR, 
Part 1 78.3; 

d) Letters and numerals shall not be less than 
3mm (0.118 in.) high, when on a metal 
certification plate and 1 2 mm (0.47 in.) on 
the portable tank, except that a portable 
tank manufactured under a previously au- 
thorized specification may continue to be 
marked with smaller markings if originally 
authorized under that specification (for 
example, DOT specification 57portable 
tanks). 



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NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



A07 S6.5.5 OWNER OR USER REQUIRED 

REPORTS FOR DOT 
SPECIFICATION 106A AND 
DOT 110A TON TANKS 

a) The Owner or User of a DOT Specifica- 
tion ton tank shall retain the certificate of 
construction(AAR-Form 4-2) and related 
papers certifying that the manufacturer 
of the specification tank identified in the 
documents is in accordance with the ap- 
plicable specification. 

b) The Owner or User shall retain the docu- 
ments throughout the period of ownership 
of the specification ton tank and for one 
year thereafter. 

c) Upon a change in ownership of the specifi- 
cation ton tank, the owner shall satisfy the 
requirements of Section 1 .3.1 5 of the ARR 
Specification. 



A07 S6.5.5.1 REPORTING OF INSPECTION 
AND TESTS FOR DOT 
SPECIFICATION 106AAND 
DOT 110A TON TANKS 

a) The Owner or User shall inspect and test 
ton tanks at frequencies specified in Table 
S6.15.3 and shall perform the inspections 
and tests in accordance with S6.1 5.3. 

b) The Owner or User is required to develop 
a written record of the results of the pres- 
sure test and visual inspection and shall 
record the information on a suitable data 
sheet. Completed copies of these reports 
shall be retained by the owner and by the 
person performing the pressure test and 
visual inspection, as long as the ton tank 
is in service. 

c) The required information to be recorded 
and checked on these data sheets are: 

1 ) Date of test and inspection; 

2) DOT Specification Number; 



3) Ton tank identification (registered sym- 
bol and serial number); 

4) Date of manufacturer and ownership 
symbol; 

5) Type of protective coating (painted, 
etc.), and statement as to need for re- 
finishing or recoating; 

6) Conditions checked, i.e., leakage, cor- 
rosion, gouges, dents or digs, broken or 
damaged chime or protective ring, fire, 
fire damage, internal condition; 

7) Test pressure; 

8) Results of tests; 

9) Disposition of ton tank (returned to 
service, returned to manufacturer for 
repair, or scraped); and 

1 0) Identification of person conducting the 
retest or inspection. 

d) If a Retest Inspection is required, the Owner 
or User shall prepare a written report in 
accordance with S6.1 5.3.6 of this supple- 
ment. 



S6.5.5.2 DOT MARKING REQUIREMENTS A07 
FOR TEST AND INSPECTION OF 
DOT SPECIFICATION 106A AND 
110A TON TANKS 

a) When a ton tank passes the required inspec- 
tion and test with acceptable results, the 
tank car facility shall mark the following 
information on the ton tank: 

1 ) Date of the inspection and test; 

2) Due date of the next inspection and 
test; 

3) The markings on the ton tank shall be 
in accordance with Appendix C of the 
ARR Specifications for Tank Cars. 



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NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



b) When a tank car facility performs multiple 
inspections and tests at the same time, one 
date may be used to satisfy the requirements 
of S6.5.5.2. Additionally, one date may be 
shown when multiple inspections and tests 
have the same due date. 



A07 S6.6 CORROSION AND FAILURE 

MECHANISMS IN TRANSPORT 

TANKS 



S6.6.3 INTERNAL AND/OR 

EXTERNAL CORROSION 



A07 



Internal and/or external wastage from corrosion 
is probably one of the most common causes of 
deterioration in transport tanks while in opera- 
tion. All metals and alloys are susceptible to 
corrosion. Corrosion is deterioration that occurs 
when a metal reacts with its environment. Cor- 
rosion can be classified based on three factors. 
These factors are: 



An effective inspection and test program re- 
quires an understanding of the applicable po- 
tential failure mechanisms and the applicable 
inspection and test methods to ensure the con- 
tinued structural integrity of a transport tank. 



A07 S6.6.1 



SCOPE 



This section provides an overview of the causes 
of deterioration and failure mechanisms in 
transport tanks. As provided in this overview, 
some forms of deterioration and failure mecha- 
nisms may include stress corrosion cracking, 
fatigue, and temperature gradients (brittle 
fracture behavior) applicable to transport tanks 
during their normal operation. 



S6.6.2 



GENERAL 



A07 a) This supplement includes a general dis- 
cussion of mechanisms and effective in- 
spection and test methods. Additionally, 
some specific guidance is given on how 
to evaluate the transport tanks for repairs, 
modifications, and continued service re- 
quirements. 

A07 b) There are a variety of inservice conditions 
that may cause deterioration of the materi- 
als used in the construction of transport 
tanks. These inservice conditions should 
be taken into consideration during any 
repair activity. Prior to any repair activity, 
it is important to identify the cause of the 
deterioration, and to prevent its re-occur- 
rence. 



a) Nature A07 

1) Wet — liquid or moisture present in the 
transport tank 

2) Dry — high temperatures that may be 
present in the transport tank 

b) Mechanism — electrochemical or direct 
chemical reactions 

c) Appearance — either uniform or local- 
ized 



S6.6.3.1 TYPES OF CORROSION A07 

To implement the proper corrective actions will 
depend on which factors caused the problems, 
making it important to diagnose the reason for 
failure. Early detection of corrosion problems 
are important to prevent failures and can be 
achieved by performing regular inspections and 
encouraging employees to be observant and 
communicate their observations. The following 
types of corrosion mechanisms are commonly 
found in transport tanks: 

a) Pitting Corrosion A07 

Pitting corrosion is the formation of holes 
in an otherwise relatively un-attacked sur- 
face. Some of the characteristics of pitting 
corrosion are: 

1) Usually a slow process causing iso- 
lated, scattered pitting over a small 
area that does not substantially weaken 



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NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



A07 the transport tank. It could, however, 

eventually cause leakage. 

2) In some cases, local corrosion pits can 
be caused by microbiological activity, 
commonly known as MIC (microbio- 
logically influenced corrosion) attack. 

3) Generally, the area of the steel sur- 
rounding a corrosion pit from MIC will 
exhibit discoloration or a ring as evi- 
dence of a thriving bacteria colony. 

A07 b) Line Corrosion 

This is a condition where pits are con- 
nected, or nearly connected to each other 
in a narrow band or line. Line corrosion 
frequently occurs in the interior surfaces 
of a transport at the following locations: 

1) the liquid-vapor interface in the trans- 
port tank, or 

2) the bottom of the transport tank. 

A07 c) General Corrosion 

This is corrosion that covers a considerable 
area of the vessel surface of the transport 
tank. When this condition occurs, the 
owner-user of the transport tanks has to 
consider if this condition has compromised 
the continued safe operation of the trans- 
port tank. The following should be used in 
making this determination: 

1 ) inspect the affected area or areas to en- 
sure that the required minimum thick- 
ness of the vessel is within acceptable 
limits; and 

2) if the affected area or areas minimum 
thickness is below tolerance, depend- 
ing on the degree of deterioration, re- 
store the area or areas to the required 
thickness by using the weld build-up 
method or a flush patch. 



d) Grooving Corrosion A07 
This type of corrosion is a form of metal de- 
terioration caused by localized corrosion, 
and may be accelerated by stress concen- 
tration. Grooving is generally noticed: 

1 ) adjacent to welded surfaces, and 

2) on flange mating surfaces. 

e) Exfoliation and Selective Leaching 

1) Exfoliation is a subsurface corrosion that 
begins on a clean surface, but spreads 
below the surface of the metal. This 
type of corrosion differs from pitting in 
that the damage to the metal exhibits a 
laminated appearance, recognized by a 
flaky and sometimes blistered surface. 

2) Selective leaching results in the removal 
of one of the elements in an alloy mate- 
rial. This corrosion mechanism is detri- 
mental because it yields a porous metal 
with poor mechanical properties. 



f) Galvanic Corrosion 



A07 



1) Occurs when two dissimilar metals 
come in contact with each other in the 
presence of an electrolyte (i.e., film of 
water containing dissolved oxygen, 
nitrogen, and carbon dioxide) constitut- 
ing an electrolytic cell. The difference 
in galvanic potential between the two 
dissimilar materials creates a local 
electrical cell that may cause rapid 
corrosion of the less noble metal. This 
corrosion mechanism becomes more 
active when there are large differences 
between the electrode potentials of the 
two metals. 

2) Galvanic corrosion may also exist with 
relatively minor changes of alloy com- 
position (i.e., between a weld metal and 
the base metal). Natural (i.e., an oxide 
coating on aluminum) or a protective 
coating may inhibit galvanic corrosion, 



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NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



but in most instances the metals or al- 
loys must be selected on the basis of 
intrinsic resistance to corrosion. 

3) In transport tanks, the effects of galvanic 
corrosion are most noticeable at welds 
or at flanged and bolted connections 
that have been exposed to contact with 
a fluid that is conductive. 

A07 g) Erosion/Corrosion 

This type of damage mechanism is generally 
attributed to the movement of a corrodent 
over a metal surface that increases the rate 
of attack due to mechanical wear and cor- 
rosion. This type of damage mechanism 
is generally characterized as having an 
appearance of smooth bottomed shallow 
pit, and may also exhibit a directional pat- 
tern or surface texture related to the path 
taken by the corrodent. This deterioration 
would normally occur at locations where 
the transport tank is filled or emptied. 

A07 h) Crevice Corrosion 



1) Environmental conditions in a crevice 
can, with time, become different to 
those on a nearby clean surface. A more 
aggressive environment may develop 
within the crevice and cause local cor- 
rosion. Crevices corrosion commonly 
can be found in: 

a. Gasket surfaces; 

b. Lap joints; and 

c. Bolts and flanges. 

2) Crevice corrosion can also be caused 
by dirt deposits, corrosion products, 
scratches in paint, etc. 



A07 



A07 



3) To avoid or greatly reduce corrosion, 
the owner-user of transport tanks, when 
having a transport tank manufactured, 
can specify materials and protection 



methods (such as coating). By imple- A07 
menting proper selection of materials 
and protection methods, corrosive at- 
tack in transport tanks can be predicted 
and controlled. However, there may be 
unexpected failures as a result of one 
or more of the following: 

a. Poor choice of materials used in 
transport tank repairs or new con- 
struction; 

b. Operating conditions different from 
those anticipated in service; 

c. Defective fabrication; 

d. Improper design; 

e. Inadequate maintenance; and 

f. Defective material. 

S6.6.4 FAILURE MECHANISMS A07 

There are various failure mechanisms that can 
result in cracks or loss of structural integrity 
to transport tanks. The more common failure 
mechanisms described below are fatigue, 
mechanical, thermal, and corrosion induced 
brittle fracture and hydrogen embrittlement, 
as a result of poor handling practices during 
welded repairs. 

a) Fatigue — Stress reversals (such as cyclic A07 
loading) in parts of transport tank equip- 
ment are common, particularly at points 
of high secondary stress. These stresses 
can originate adjacent to locations of weld 
repairs and from over the road vibratory 
stresses. If stresses are high and reversals 
frequent, failure of parts may occur because 
of mechanical fatigue crack propagation. 
Fatigue failures in transport tanks may also 
result from exposure to cyclic temperature 
and pressure changes. Locations where met- 
als having different thermal coefficients of 



2 1 □ 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



expansion that are joined by welding may 
be susceptible to thermal fatigue upon ex- 
posure to service temperature variations. 

A07 1) In specific cases where the combined 
effects of exposure to a corrosive en- 
vironment and cyclic loading occur 
together in a transport tank, the damage 
mechanism that can occur is corrosion 
assisted fatigue or simply corrosion 
fatigue. 

A07 2) Corrosion fatigue crack propagation 
typically occurs along a straight direc- 
tion, with minimal branching. Some 
sources of fatigue crack initiation are: 

a. At sharp corners; 

b. At openings in the transport tank; 
and 

c. At structural attachments. 

A07 b) Temperature — At subfreezing tempera- 
tures, water and some chemicals handled 
in transport tanks may freeze and cause 
failure. Carbon and low-alloy steels may 
be susceptible to brittle fracture, even at 
ambient temperatures. A number of failures 
have been attributed to brittle fracture of 
steels that were exposed to temperatures 
below their ductile-to-brittle (DBTT) transi- 
tion temperature during a pressure lest or 
hydrostatic test. However, most brittle frac- 
tures have occurred on the first application 
of a particular stress level (that is, the first 
hydrostatic test or overload). 

A07 1) Special attention should be given to 
low-alloy steels because they are prone 
to temper embrittlement, which can 
result in a loss of toughness. 

a. Temper embrittlement is defined as 
a loss of ductility and notch tough- 
ness due to postweld heat treatment 
or high temperature service, above 
370°C (700°F). 



c) Hydrogen Embrittlement — A loss of A07 
strength and/or ductility in steels caused by 
atomic hydrogen dissolved in the steel. It 

is a low temperature phenomenon, seldom 
encountered above 95°C (200°F), and most 
often occurs as a result of hydrogen evolved 
from aqueous corrosion reactions or hy- 
drogen generated during welding. Weld 
underbead cracking (also know as delayed 
cracking and cold cracking) is also a form 
of hydrogen embrittlement; however, in this 
case, the hydrogen comes from the weld- 
ing operation rather than from a corrosion 
reaction. 

1) Weld underbead cracking is caused A07 
by hydrogen dissolved in a hard, high 
strength weld heat-affected zone. Use 

of low hydrogen welding practices to 
minimize dissolved hydrogen, and/or 
use of high preheat, and/or postweld 
heat treatment to reduce heat-affected 
zone hardness, will reduce the likeli- 
hood of weld underbead cracking in 
susceptible steel. 

2) \ lydrogen embrittlement is reversible A07 
as long as no physical damage, e.g., 
cracking, has occurred in the steel. If 

the atomic hydrogen is removed from 
the steel before any damage occurs, 
for example by heating for a short time 
in the absence of hydrogen between 
I50°C (300 n F) and 205°C (400 C F), 
normal mechanical properties will be 
restored. 

3) Welding procedures, repair methods, A07 
and inspection procedures must in- 
clude careful consideration of poten- 
tial failure in corrosive environments, 
including the various forms of hydrogen 
embrittlement. 

d) Stress Corrosion Cracking (SCO — Crack- A07 
ing of a metal caused by the combined ac- 
tion of stress and a corrosive environment. 
SCC only occurs with specific combina- 
tions of metal and environment. The stress 



2 i i 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



required may be either applied or residual. 
Examples of stress corrosion cracking in- 
clude chloride stress corrosion cracking 
of stainless steels in hot, aqueous chloride 
solutions; caustic cracking of carbon steel 
in hot sodium hydroxide solutions, and 
ammonia stress corrosion cracking of brass 
in ammonia solutions (season cracking). 

A07 1 ) Corrosivily alone is not a good indicator 
of the likelihood of a particular environ- 
ment to cause SCC in a particular metal. 
Solutions that are highly corrosive to a 
material almost never promote SCC. 

A07 2) The principal variables affecting SCC 
are tensile stress, service temperature, 
solution chemistry, duration of expo- 
sure, and metal properties. Removing 
any one of these parameters sufficiently 
can reduce or eliminate the possibility 
of SCC occurring in service. 



S6.7 



CLASSIFICATION BOUNDARIES 



a) Transport tanks are classified as Class 1, 
Class 2, and Class 3. The classification is 
established by the applicable Modal Ap- 
pendix of Section XII of the ASME Boiler 
and Pressure Vessel Code. Also contained in 
the Modal Appendix is the type of Inspec- 
tor, i.e., Authorized Inspector, Qualified 
Inspector, and Certified Individual, that is 
permitted to perform the applicable fabri- 
cation inspection of the transport tank, i.e., 
cargo tank, tank car, portable tank, and 
ton tank. The classification of the transport 
tank, except for continued service inspec- 
tions determines the code of construction 
requirements for repairs or modifications. 



S6.8 PRESSURE, TEMPERATURE, AND 

CAPACITY REQUIREMENTS FOR 

TRANSPORT TANKS 

a) Section XII has established pressure, tem- 
perature, and maximum thickness require- 
ments for transport tanks as follows: 



1) Pressure: full vacuum to 208 bar (full 
vacuum to 3,000 psia); 

2) Temperature: -269°C to 343°C (-452°F 
to 650°F); and 

3) Maximum material thickness: 38 mm 
(1-1/2 in.). 

b) Transport tanks manufactured prior to the 
adoption of ASME Section XII by the Com- 
petent Authority were manufactured in 
accordance with ASME Section VII I, Div. 1. 
Transport tanks manufactured to this Code 
were required to be stamped with the "U" 
Code Symbol Stamp in accordance with 
Section VIII, Div. 1, if the design pressure 
of the transport tank was 241 kPa (35 psi) 
(depending on material being transported) 
and greater. If the design pressure was less 
than 241 kPa (35 psi) (depending on the 
media being transported), the transport 
tank was constructed in accordance with 
Section VIII, Div. 1, but not stamped with 
the "U" Code Symbol Stamp. 

c) For these transport tanks, the requirements 
established in this part for continued service 
inspection, repairs, or modifications shall 
apply, unless specifically exempted by the 
DOT. 



S6.9 REFERENCE TO OTHER CODES 

AND STANDARDS 

Other existing inspection codes, standards, and 
practices pertaining to the continued service 
inspection, i.e., CFR 49, Parts 100 through 
1 85, ASMF Section XII, etc., of transport tanks 
can provide useful information and references 
relative to the inspection techniques listed in 
this appendix. Additionally, supplementary 
guidelines for assisting in the evaluation of in- 
spection results and findings are also available. 
Some acceptable requirements and guidelines 
are as follows: 

a) American Society of Mechanical Engineers 
— ASMP Boiler and Pressure Vessel Code, 



z i z 



NATIONAL BDARD INSPECTION CODE • PART Z 



INSPECTION 



TableS6.13 

Periodic Inspections and Tests 



Test or Inspection 

(cargo tank specification, configuration, and service) 


Date by which first test 
must be completed 
(see Note 1 ) 


Interval period 
after first test 


TxternalVisual Inspection ' ;; 


; . : . : : : - ^ : : .'■';■ 

All cargo tanks designed to be loaded by vacuum with 
full opening rear heads 


September 1, 1991 


6 Months 


All other cargo tanks 


September 1, 1991 


1 Year 


''1nE:er?Tai':Visua);.!nspection:\ 


All insulated cargo tanks, except MC 330, 
MC331, & MC 338 (see Note 4) 


September 1, 1991 


1 Year 


All cargo tanks transporting lading corrosive to the tank 


September 1, 1991 


1 Year 


All other cargo tanks, except MC 338 


September 1, 1995 


5 Years 


■Jjftjtig Inspection^, 


All lined cargo tanks transporting lading corrosive 
to the tank 


September 1, 1991 


1 Year 


Leakage TesfV : ! : ' : „ 


MC 330 and MC 331 cargo tanks in chlorine service | September 1, 1991 


2 Years 


All other cargo tanks, except MC 338 September 1, 1991 


1 Year 


; Pressure Test ■ : : .;'.' : ." : ■ "' ■;■':.' ;■■■ 


Hydrostatic or Pneumatic (see Notes 2 and 3) 


— I — 


All cargo tanks which are insulated with no manhole or 
insulated and lined, except MC 338 


September 1, 1991 


1 Year 


All cargo tanks designed to be loaded by vacuum with 
full opening heads 


September 1 , 1 992 


2 Years 


MC 330 and MC 331 cargo tanks in chlorine service 


September 1 , 1 992 


2 Years 


All other cargo tanks 


September 1, 1995 


5 Years 


Thickness Test "'■ \ 


All unlined cargo tanks transporting material corrosive to 
the tank, except MC 338 


September 1 , 1 992 


2 Years 


Note 1 : If a cargo tank is subject to an applicable inspection or test requirement under the regulations in effect 
on December 30, 1990, and the due date (as specified by a requirement in effect on December 30, 1990) for 
completing the required test occurs before the compliance date listed in the Table, the earlier date applies. 
Note 2: Pressure testing is not required for MC 300 and MC 331 cargo tanks in dedicated sodium metal service. 
Note 3: Pressure testing is not required for uninsulated lined cargo tanks with a design pressure of MAWP 1 03 
kPa (1 5 psi) or less, which receive an external visual inspection and lining inspection at least once each year. 
Note 4: Insulated cargo tanks equipped with manholes or inspection openings may receive either an internal 
visual inspection in conjunction with the external visual inspection or a hydrostatic or pneumatic test of the 
cargo tank. 



2 1 7 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



nozzle attachments, and, if equipped, 
baffles, internal stiffeners, surge protec- 
tion devices for defects, corrosion, and 
missing or loose attachment; 

2) Lined, coated, or if the cargo tank is 
so designed to preclude an internal 
visual inspection — If the cargo tank is 
externally lined, coated, or of a design 
that would prevent a complete and 
thorough external visual examination, 
the internal areas of the cargo tank that 
are not obstructed by the lining Or coat- 
ing shall be internally inspected; 

3) Lined, coated, or if the cargo tank is 
so designed to preclude access to the 
internal surfaces — The cargo tank shall 
be subjected to a hydrostatic or pneu- 
matic test in accordance with S6.13.6 
of Lhis section; 



TabIeS6.13.1-a 

Inservice Minimum Thicknesses for Steel and Steel 



4) All corroded or abraded areas of a cargo 
tank wall must be thickness tested in 
accordance with the following proce- 
dures: 

a. Measurements must be made us- 
ing a device capable of accurately 
measuring thickness within + 0.051 
mm (± 0.002 of an inch); 

b. Any individual performing thickness 
testing must be trained in the proper 
use of the thickness testing device in 
accordance with the testing device 
manufacturer's instructions; 



c. 



The minimum thickness require- 
ments for the heads, shell baffle, 
and bulkhead, when used as tank 
reinforcement, shall meet the mini- 
mum thickness requirements for in- 
service requirements for cargo tank 
specifications MC 300, MC 303, 
MC 304, MC 306, MC 307, MC 



Alloys 



Minimum manufactured thickness (US "Manufacturers' 
Standard Gage for Steel Sheets" or inches) 


Nominal decimal 
equivalent, mm 
(inches) 


Inservice minimum 
reference, mm 
(inches) 


!'^:V.^ J ■:>'"'VV™^vC^^t^^^':^Vv"v^:|-:>1■'^^^. , .'' i 


I.0bl0.0418i 


0.')- (0.038! 


1 8 gage 


1.21 (0.0478) 


1.09(0.043) 


,:• ; 17 gage 


■■ : 1.37f0;O538); ;v- 


"7 ;/...; i;22.(b^048>Y.: ; :' 


1 6 gage 


1.52 (0.0598) 


1.37(0.054) 


v;.,.;.1.5,|a;ge.:: .-.; 


1.71 (0.0673) 


1.55 (0.061) 


1 4 gage 


1.90(0.0747) 


I 70 I0.067) 


.:,-• iSgage ' 


2.2K.0.0o<r. 


: : : zm (0.081 }"'-:■;. 


1 2 gage 


2.66(0.1046) 


2.39 (0.094) 


;,\ 11 gage;.;-,. 


I.04 .0.1 I4f,i 


2.-4.0.1(18. 


1 gage 


3.42 (0.1345) 


3.07(0.121) 


;;''■:'''■■:■■;■■ Y> .:,; : 9gegc. ; 7 ■'■',v:.:-/y ! . 


> 80(0.1 (95) 


5.4 1.0.1 15. 


8 gage 


4.18(0.1644) 


3.76(0.148) 


^^"'"' 4 ■^">^ F >>^*'^^v?>^^>;^>;<<^''^\v;^:^^'<> t ' 


'■■■" :■'■: '4:s5,(o:i,793) , "7 v , 


■■■■,..4.05 ta:imr\ v,. 


3/1 6 inch 


5 (0.1875) 


1.29(0.169) 


I/4 inch 


(» ■■0.2 500. 


5.72(0.225) 


5/16 inch 


8(0.3125) 


7.14(0.281) 


.;...- 3/8 inch:: ■■ 


... ' ' 1040.3750)' ".. 


::..;.'■■. 8.59(0.338) 



2 1 B 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



S6.13.2 



310, MC 311 transport tanks, and 
MC 312 cargo tanks constructed 
of steel, steel alloys, aluminum, 
and aluminum alloys are based on 
90% of the minimum manufac- 
tured thickness. Table S6.13.1-a, 
provides minimum inservice mini- 
mum thicknesses for steel and steel 
alloys. Table S6.13.1-b provides 
minimum thicknesses for aluminum 
and aluminum alloys. 



INSPECTION OF PIPING, 
VALVES, AND MANHOLES 



The cargo tank piping, valves, and gaskets 
must be carefully inspected for corroded ar- 
eas and the piping system and valve attach- 
ment welds or threads must be inspected 
for corrosion, leakage, or any other defects 
that might render the cargo tank unsafe for 



transportation service. This examination 
shall include: 

b) All devices for securing manhole covers 
must be in satisfactory working condition, 
and the area must not show any evidence 
of leakage at either the manhole cover or 
the manhole gasket. 

1) When inspecting gaskets on any full 
opening of the cargo tank, the inspector 
should visually examine the gasket for 
defects to include cracks and/or splits 
that may prevent the gasket material 
from sealing properly. 

2) If the gasket shows any evidence of cuts 
or cracks that are likely to cause failure, 
the gasket shall be replaced. 

c) All emergency devices and valves includ- 
ing self-closing stop valves, excess flow 



Table S6.1 3.1 -b 

Inservice Minimum Thicknesses for Aluminunvand AluminumAiloys 



Minimum manufactured thickness, mm 
(inches) 


Inservice minimum thickness, mm 
(inches) 


>'■, rM'&.Q7S]y^y : ^:y : y:/i 


1.78(0.070) 


2.21 (0.087) 


1.98(0.078) 


2.44 (0.096I 


,-'■■-"> 2;i§Hjpt(l86):V,' ■'."'■ '■.\."C 


2.77(0.109) 


2.49(0.098) 


3.30(0.130) 


-?^: i-'i[WMim''^-- : -' : ^"" 


3.58(0.141) 


3.23 (0.127) 


\:;3;84,(:Q,tS4)/.; 


■ ,'Jv : : 3-45- (6v13|) ; v,, ; / 


4.37(0.172) 


3.94(0.155) 


4.39(0.173) 


t' ; ''';; , K^:9C§^.s&) , ^7 ;: ^ : ' ,, '^7; , ';A; , ' : ''-''C 


4.93 (0.194) 


4.44(0.175) 


5.49(0.216) 


?\^:?/ -•;-... J ■;■;-■ 4)9 imm y>f:>i 




6.02 (0.237) 


5.41 (0.213) 


), ;*' ''■ 6.86(0.270i : '';' 


\ ; ;' : :■-■:'■?■ ..6.1 7 (0.243). ..." 


9.14(0.360) 


8.23 (0.324) 


.: ■ ; ;; ■::.;. .:' ; ; ' J ■ :' ; t i -4 b; < q^41 "' - : -, v - . 


I0.3D ;i>.4o.Si 


13.70(0.540) 


12.30(0.486) 


.■■■ ■ .'■'".'.■" ' . 



Z 1 9 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



valves, and remote closure devices must 
be free of corrosion, distortion, erosion, 
and any external damage that will prevent 
safe operation of the cargo tank. Remote 
closure devices and self-closing stop valves 
must be operated during inspection to 
demonstrate that the devices arc operating 
as designed. 

d) Any missing bolts, nuts, and fusible links 
or elements shall be replaced. Loose bolts 
and nuts must be tightened. 

e) All re-closing pressure relief valves shall 
be externally inspected for any corrosion 
or damage that might prevent the device 
from operating as designed. 

1 ) All re-closing pressure relief valves on 
cargo tanks carrying lading corrosive 
to the pressure relief valve shall be 
removed from the cargo tank for inspec- 
tion and testing. 

2) Each re-closing pressure relief valve 
required to be removed and tested as 
specified in (e)(1) above must open at 
the required test pressure and reseat to 
a leak-tight condition at 90% of the set- 
to-discharge pressure or the pressure 
prescribed for the applicable cargo tank 
specifications. 



S6.13.3 INSPECTION OF 

APPURTENANCES AND 
STRUCTURAL ATTACHMENTS 

a) Major appurtenances, as defined in CFR 
49, 1 80.407 (d)(2)(viii), include but are not 
limited to suspension system attachments, 
connecting structures, and those elements 
of the upper coupler (kingpin) assembly that 
can be inspected without dismantling the 
upper coupler (kingpin) assembly. Major 
appurtenances shall be inspected for any 
corrosion or damage that might prevent safe 
operations. 



b) If the cargo tank transports lading that is 
corrosive to the cargo tank, the upper cou- 
pler (kingpin) assembly must be inspected 
at least once in a two year period. The up- 
per coupler (kingpin) shall be removed for 
inspection of the following: 

1 ) Corroded and abraded areas; 

2) Dents; 

3) Distortions; 

4) Weld failures; and 

5) Any other condition that might render 
the cargo tank unsafe for transportation 
service. 

c) If the cargo tank is constructed of mild or 
high strength low alloy steel and employs 
ring stiffeners or other appurtenances that 
create air cavities adjacent to the ring stiff- 
eners or other appurtenances to the cargo 
tanks shell and these areas cannot be visu- 
ally externally inspected, then the following 
shall be performed: 

1) A thickness test on the stiffener rings 
shall be performed at least once every 
two years of at least four symmetrically 
distributed readings to establish an 
average thickness for the ring stiffener 
or appurtenance. The thickness require- 
ments are specified in Tables S6. 1 3 . 1 -a 
or S6.1 3.1-b, as applicable; 

2) If any of the thickness testing readings 
for the ring stiffeners are less than the 
average thickness by more than 10%, 
thickness testing must be performed 
from inside the transport tank on the 
area of the tank wall covered by the 
appurtenance or ring stiffener. If the re- 
sults of the thickness test of the transport 
tank fail to conform to the minimum 
thickness requirements prescribed for 
the design as manufactured, the tank 



22D 



NATIONAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



must be repaired or removed from haz- 
ardous material service. The owner of 
the transport tank can de-rate the tank 
to transport authorized material and 
reduced maximum weight of lading, re- 
duce pressure, or a combination thereof 
under the following conditions: 

a. The reduced loadings based on the 
cargo tanks design conditions and 
material thicknesses are appropri- 
ate for the reduced loading condi- 
tions. This reduced loading shall be 
certified by a Design Certifying En- 
gineer, and a revised manufacturer's 
certificate shall be issued reflecting 
these reduced loading conditions; 

b. The cargo tank motor vehicle's 
manufacturer's nameplate shall 
be revised to reflect the reduced 
limits; 

c. If (a) and (b) above cannot be satis- 
fied, the owner of the cargo tank 
should not return the cargo lank 
to hazardous material service. The 
owner shall remove, or obliterate, 
or in a secure manner cover the 
tank's specification plate; and 

d. The inspector shall record the re- 
sults of the thickness test on the 
cargo tank's inspection report. 



S6.13.4 VISUAL INTERNAL INSPECTION 

When performing an internal visual inspection 
of a cargo tank and the cargo tank is equipped 
with a manhole or an inspection opening, the 
inspector shall examine the internal surfaces for 
corroded and abraded areas, dents, distortions, 
defects in welds, and any other conditions that 
might render the cargo tank unsafe for trans- 
portation service. As a minimum the inspection 
shall include: 

a) The cargo tank shell and heads; 



b) If equipped, the cargo tank corrosion- 
resistant liner must be inspected at least 
once a year. The inspection shall include 
procedures for rubber liners and liners 
other than rubber (elastomeric materials). 
The requirements for lining inspections are 
provided in Table S6.13.4 of this section; 
and 

c) If the cargo tank is not equipped with a 
manhole or inspection opening, the cargo 
tank shall be subjected to a hydrostatic or 
pneumatic test as provided inTableS6.13.4 
of this section. 



S6.13.5 LINING INSPECTIONS 

Cargo tank linings include rubber linings and 
linings other than rubber (elastomeric materials) 
that are used to protect the tank from corrosion 
or other harmful effects of the lading material 
being transported. The inspection requirements 
are: 

a) Rubber linings must be inspected for holes 
by using a high frequency spark tester, as 
described in this section. If holes are found, 
they must be repaired using equipment 
and procedures prescribed by the lining 
manufacturer or lining installer; 

b) Linings other than rubber (elastomeric ma- 
terials) must be inspected and tested in ac- 
cordance with procedures using equipment 
and procedures prescribed by the lining 
manufacturer or lining installers; and 

c) If degraded or defective areas of the cargo 
lank lining are discovered, the lining in 
these areas shall be removed and the thick- 
ness of the cargo tank wall area under the 
lining defect shall be tested in accordance 
with the following: 

1) Measurements shall be made using a 
device capable of accurately measur- 
ing thickness to within ± 0.051 mm (+ 
0.002 of an inch); 



22 i 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Table S6.1 3.4 

Periodic Inspections and Tests 

Test or Inspection 

(cargo tank specification, configuration, and service) 



External Visual Inspection 



All cargo tanks designed to be loaded by vacuum with 
full opening rear heads 



All other cargo tanks 



Internal Visual Inspection 



All insulated cargo tanks, except MC 330, 
MC331, &MC338 



All cargo tanks transp orting lading corrosive to the tank 
All other cargo tanks, except MC 338 

Lining inspection.; ^'" c . ■.-, -i ■■- :■'& i;: : , . 



All lined cargo tanks transporting lading corrosive 
to the cargo tank 



Leakage Test 



MC 330 and MC 331 cargo tanks in chlorine servic 



All other cargo tanks, except MC 338 



Pressure Test *...-... 

(Note I: sodium metal; Note '*: \/tAWP - 



>-., 



All cargo tanks which are insulated with no manhole or 
insulated and lined, except MC 338 



All cargo tanks designed to be loaded by full vacuum 
with full opening in the rear head of the cargo tank 

MC 330 and MC 331 cargo tanks in chlorine service 



All other cargo tanks 



Thickness Test 



All unlined cargo tanks in corrosive service, 
except MC 338 



Test and Inspection Interval 
After Original Certification 
Date 



6 Months 



1 Year 



1 Year 



Year 



5 Years 



1 Year 



2 Years 



1 Year 



1 Year 



2 Years 



2 Years 



i Years 



2 Years 



Note 1: Pressure testing is not required for MC 300 and MC 331 cargo tanks in dedicated 
sodium metal service. 

Note 2: Pressure testing is not required for uninsulated lined cargo tanks with a design pres- 
sure of MAWP 103 kPa (15 psi) or less, which receive an external visual inpsection and lining 
inspection at least once each year. 



222 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



The individuals performing the thick- 
ness test must be trained in the proper 
use of the thickness testing device in 
accordance with the manufacturer's 
instructions; and 

The minimum inservice thickness re- 
quirements for series MC 300 cargo 
tanks for steel and steel alloy and alu- 
minum and aluminum alloy material 
is specified in Tables S6.1 3.1 -a and 
S6.13.1-b. 



S6.13.6 PRESSURE TESTS 

Cargo tanks may be tested by either the hy- 
drostatic or pneumatic test method. When 
performing a pressure test, the test procedure 
shall include the test method (hydrostatic or 
pneumatic) used for the cargo tank, and the 
test shall include all appurtenance, all baffles, 
bulkheads, and upper coupler (fifth wheel) that 
comprise the cargo tank and shall be pressure 
tested at pressures established in Table S6.1 3.6. 



The pressure test procedure shall include the 
following: 

a) The pressure test shall be performed in ac- 
cordance with a test pressure that includes 
provision for the inspector to perform an 
internal and external visual inspection of 
all surfaces of the cargo tank. For MC 338 
cargo tanks, and cargo tanks not equipped 
with a manhole, an internal visual inspec- 
tion is not required. 

1) The visual external inspection shall 
be conducted while the cargo tank is 
under test pressure. 

2) The visual internal inspection shall 
be conducted after the pressure test is 
completed. 

b) When performing the pressure test all self- 
closing pressure relief valves, including 
emergency relief vents, and normal vents 
shall be removed for inspection and test, 
except for line safety devices that may be A07 
removed or left in place. 



Table S6.1 3.6 

Pressure Test Requirements 



Cargo Tank Specification 


Test Pressure 


MC 300, MC 301 , MC 302, MC 303, 
MC 305, and MC 306 


20.7 kPa (3 psig) or design pressure, 
whichever is greater 


MC 304 and MC 307 


275.8 kPa (40 psig) or 1 .5 times design 
pressure, whichever is greater 


MC310, MC311, and MC 312 


20.7 kPa (3 psig) or 1 .5 times design pressure, 
whichever is greater 


MC 330 and MC 331 1 .5 times either MAWP or the re-rated 

j pressure, whichever is applicable 


MC 338 i 1 .25 times either MAWP or the re-rated 

i pressure, whichever is applicable 


DOT 406 j 34.5 kPa (5 psig) or 1 .5 times the MAWP, 

j whichever is greater 


DOT 407 


275.8 kPa (40 psig) or 1 .5 times the MAWP, 
whichever is greater 


DOT 412 


1.5 times the MAWP 



223 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



1) Each self-closing pressure relief valve 
that is an emergency relief vent shall 
be capable of opening at the required 
set pressure and scat to a leak-tight 
condition at 90% of the set-to-discharge 
pressure, or the pressure prescribed for 
the applicable cargo tank. It should be 
noted that self-closing pressure relief 
valves not tested or failing the pressure 
lest must be repaired or replaced; 

2) Normal vents 6.895 kPa (1 psig) shall be 
tested according to the testing criteria 
established by the valve manufacturer. 

c) If the cargo tank is not carrying a corrosive 
lading, all areas that are covered by the 
upper coupler (fifth wheel) assembly must 
be inspected for corroded, abraded areas, 
dents, distortions, defects in welds, and any 
other condition that might render the tank 
unsafe for transport service. The upper cou- 
pler (fifth wheel) assembly must be removed 
from the cargo tank for this inspection. 

d) If the cargo tank motor vehicle has multiple 
cargo tanks, each cargo tank shall be tested 
separately. The adjacent cargo tanks shall 
be empty and at atmospheric pressure. 

e) When performing the hydrostatic or pneu- 
matic test, the following requirements shall 
be specified in the test procedure: 

1 ) All closures, except the pressure relief 
device shall be in place during the 
test; 

2) All required loading and unloading 
venting devices that are rated less than 
the test pressure may be removed dur- 
ing the test, or: 

a. If the venting devices are not 
removed, the device shall be ren- 
dered inoperative by clamps, plugs, 
or other equally effective restrain- 
ing devices; 



b. The restraining devices shall not 
prevent detection of leaks or dam- 
age of the venting device and shall 
be removed immediately after the 
test. 



S6.1 3.6.1 HYDROSTATIC OR PNEUMATIC 
TEST METHOD 

a) The owner or user of the cargo tank may 
either apply the hydrostatic or pneumatic 
test method to satisfy the requirements of 
the pressure test specified in Table S6.13.4 
of this section. 

b) If the hydrostatic test method is used, the 
cargo tank shall be completely filled in- 
cluding, if equipped, its dome with water 
or other liquids having similar viscosity. 
During the hydrostatic test, the inspector 
shall: 

1 ) Ensure that the cargo tank is completely 
filled and free of any air pockets. During 
this operation, the liquid should flow 
freely out of the cargo tanks test vent; 

2) Ensure that the temperature of the test 
media does not exceed 38°C (1 00° F); 

3) Ensure that the test pressure can not 
exceed the test pressures specified in 
Table S6. 13.6; 

4) Ascertain that the test pressure shall 
be maintained for a minimum of 10 
minutes; and 

5) Visually examine the cargo tank for 
leakage, bulging or other defects. If any 
of the proceeding occurs, terminate the 
test, drain the cargo tank, and evaluate 
the cargo tanks capabilities for repair or 
replacement of the affected areas. 

c) If the owner and/or user elect to use the 
pneumatic test method, precaution should 



224 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



be employed due the possibility of failure of 
the cargo tank under pneumatic test pressure 
conditions. The test area should be limited 
to the authorized personnel only and the 
test personnel shall be experienced in the 
pneumatic testing method. The pneumatic 
test pressure for the cargo tank shall be: 

1 ) gradually increased to one-half the test 
pressure; 

2) after reaching one-half the test pressure, 
the test pressure shall be increased at 
rate of approximately one-tenth of the 
test pressure until the test pressure is 
reached. The test pressure shall not 
exceed the test pressures specified in 
Table S6. 13.6; 

3) when the test pressure is reached, the 
test pressure shall be held for a least 5 
minutes, then reduced to the MAWP of 
the cargo tank; 

4) at MAWP the inspector shall examine 
the cargo tank for any leakage, bulging, 
or any other defects; and 

5) visually examine the cargo tank for 
leakage, bulging, or other defects. If any 
of the preceeding occurs, terminate the 
lest, drain the cargo tank of all air or 
inert gas, and evaluate the cargo tanks 
suitability for repairs or replacement of 
the affected areas. 



S6.13.6.2 PRESSURE TESTING INSULATED 
CARGO TANKS 

a) When pressure testing an insulated cargo 
tank, the insulations and jacketing are not 
required to be removed, unless it is not pos- 
sible to reach the test pressure and maintain 
a condition of pressure equilibrium after 
the test pressure is reached, or the vacuum 
integrity cannot be maintained in the insu- 
lation space. 



b) For MC 338 cargo tanks that transport re- 
frigerated liquid, flammable gas, or oxygen, 
if the cargo tank is opened for any reason, 
the cleanliness of the cargo tank shall be 
verified prior to closure as required by CFR 
Title 49, Part 178.338-15. 



S6.1 3.6.3 PRESSURE TESTING CARGO 
TANKS CONSTRUCTED OF 
QUENCHED AND TEMPERED 

STEELS 

When testing MC 330 and MC 331 cargo tanks 
constructed of quenched and tempered steels, 
in accordance with ASME Section XII, Modal 
Appendix 1, and for cargo tanks constructed 
prior to the adoption of ASME Section XII, 
Part UHT of ASME Section VIII, Div. 1, of the 
ASME Boiler and Pressure Vessel Code, or con- 
structed of other quenched and tempered steel, 
without postweld heat treatment, used for the 
transportation of anhydrous ammonia or any 
other hazardous material that are subject to 
stress corrosion cracking, and the transporta- 
tion of liquefied petroleum gas, the following 
is required: 

a) The cargo tanks must be subjected to an 
internal visual inspection of all internal 
surfaces of the cargo tank using the wet 
fluorescent magnetic particle examination 
method immediately prior to performing 
the required pressure test; 

b) The fluorescent magnetic particle exami- 
nation has to be performed in accordance 
with ASME Section V of the Boiler and 
Pressure Vessel Code; 

c) The required pressure test as specified in 
Table S6.1 3.4 shall be required. 



225 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



S6.13.6.4 PRESSURE TESTING CARGO 
TANKS EQUIPPED WITH A 
HEATING SYSTEM 

If the cargo tank is equipped with a heating 
system, employing a medium such as, but not 
limited to, steam or hot water hydrostatically, 
pressure is as follows: 

a) The cargo tank must be tested at least once 
every five years; 

b) The test pressure for the heating system shall 
be at least to the maximum system design 
operating pressure; 

c) The test pressure shall be maintained for a 
least 5 minutes; and 

d) If the heating system employs flues for heat- 
ing the lading, the flues must be tested to 
ensure that the lading cannot leak into the 
flues or into the atmosphere. 



that might render the cargo tank unsafe for 
transportation service. 

b) If the cargo tank does not satisfy the require- 
ments for the pressure test of the heating 
system identified in (a) above, the cargo 
tank can not be returned to transportation 
service, unless: 

1) Cargo tanks with a heating system, 
which does not hold pressure, should 
remain inservice as an unheated cargo 
tank, if the heating system remains in 
place and is structurally sound and no 
lading may leak into the heating system; 
and 

2) The specification information for the 
heating system on the namcplate is 
changed to indicate that the cargo tank 
has no working heating system. 



S6.1 3.6.7 INSPECTION REPORT 



S6.1 3.6.5 EXCEPTIONS TO PRESSURE 
TESTING 

a) MC 330 and MC 331 cargo tanks are not 
required to be pressure tested that are in 
dedicated sodium metal service. 

b) Un-insulated cargo tanks, with a design 
pressure or MAWP of 103 kPa (15 psig) 
or less, which can be externally visually 
inspected and a lining inspection at least 
once every five years, are not required to 
be pressure tested. 



S6.1 3.6.6 ACCEPTANCE CRITERIA 

a) The acceptance criteria for the hydrostatic 
or pneumatic pressure test of the heating 
system is based on the cargo tanks capabili- 
ties to successfully pass the pressure test, 
without showing evidence of permanent 
distortion or other evidence of weakness 



a) The Inspector shall prepare a written inspec- 
tion report that identifies the results of the 
pressure test and specifies the following: 

1) Manufacturer's serial number of the 
cargo tank; 

2) Name of the cargo tank manufacturer; 

3) DOT or MC specification number; 

4) MAWP of the cargo tank; 

5) Minimum thickness of the head and 
shell of the cargo lank; 

6) Identify whether the cargo tank is lined, 
insulated, or both; and 

7) Identify if the cargo tank is for special 
service, i.e., transport material cor- 
rosive to the cargo lank, dedicated 
service, etc. 



226 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



c) The leakage test shall be maintained for a 
minimum of five minutes; 

d) Cargo tanks in liquefied compressed gas 
service shall be: 

1) Inspected externally for leaks during 
the leakage test; 

2) Suitable safeguards must be provided 
to protect personnel should a failure 
occur, as follows: 

a. Cargo tanks may be leakage tested 
with the hazardous material in the 
cargo tank during the test; 

b. The leakage test pressure shall not 
be less than 80% of the MAVVP 
marked on the specification plate, 
unless the cargo tank has a MAVVP 
of 690 kPa (60 psig) or more, in 
which case it should be leak tested 
at its maximum normal operating 
pressure provided it is in dedicated 
service or services; 

c. MC 330 or MC 331 cargo tanks in 
dedicated liquefied petroleum gas 
service may be leakage tested at not 
less than 414 kPa (60 psig); 

d. An operator of a MC330orMC331 
cargo tank and a non-specification 
cargo tank equipped with a meter 
should check leak tightness of the 
internal self-closing stop valve by 
conducting a meter creep test; 

e. A non-specification cargo tank is 
a cargo tank that conforms and is 
marked in conformance with the 
edition of the ASME Code in effect 
when the cargo tank was fabricated 
and should be used for the transpor- 
tation of liquefied petroleum gas, 
provided the cargo tanks satisfies 
the following: 



1. The cargo tank has a mini- 
mum design pressure no 
lower than 1 72 kPa (250 psig); 

2. The cargo tank has a water 
capacity of 13,247.5 I (3500 
gallons) or less. 

3) The cargo tank has been manufactured 
in accordance with the ASME Code 
prior to January 1, 1981. This require- 
ment requires the cargo tank to be 
stamped with the ASME Code Symbol 
Stamp and documented on an ASME 
Manufacturer's Data Report; 

4) The cargo tank shall conform to the 
applicable provisions of NFPA 58, 
except if NFPA is inconsistent with the 
requirements of Parts 178 and 180 of 
Title 49; 

5) The cargo tank shall be leakage tested 
in accordance with Table S6.1 3.4; 

6) MC 330 and MC 331 cargo tanks in 
dedicated service for anhydrous am- 
monia may be leakage tested at not less 
than 414 kPa (60 psig); 

7) Non-specification cargo tanks must be 
leakage tested at pressure of not less 
than 16.6 kPa (2.4 psig), if the cargo 
tanks complies with one of the follow- 
ing: 

a. For the transport of petroleum prod- 
ucts that have a liquid capacity of 
13,250 I (3500 gal); 

b. Permanently secured non-bulk 
tanks to a motor vehicle and pro- 
tected against leakage or damage 
in the event of turnover, having a 
liquid capacity of less than 450 I 
(119 gal), used for transportation 
of a flammable liquid petroleum 
product. 



229 



NATIDNAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



8) The cargo tank is used to transport pe- 
troleum distillate fuels that are equipped 
with a vapor collection equipment and 
should be leakage tested in accordance 
with the Environmental Protection 
Agency's "Model 27-Determination of 
Vapor Tightness of Gasoline Delivery 
Tank Using Pressure- Vacuum Test," as 
follows: 

a. The test method and procedures 
and maximum allowable pressure 
and vacuum changes are in 40 CFR 
63.425(e)(1); 

b. The hydrostatic test alternative, 
using liquid in Environmental 
Protection Agency's "Method 27- 
Determination of Vapor Tightness 
of Gasoline Delivery Tank Using 
Pressure- Vacuum Test" should not 
be used to satisfy the leak testing 
requirements of this section. The 
test shall be conducted using air; 

c. Cargo tanks equipped with vapor 
collection equipment should be 
leakage tested in accordance with 
(8)(b) above. 

9) Cargo tanks that fail to retain leakage 
test pressure shall not be returned to 
service as a specification cargo tank, 
unless all sources of leakage are proper- 
ly repaired prior to returning the cargo 
tank to hazardous material service. 

1 0) It is required that after July 1 , 2000, that 
the Registered Inspector that performs 
inspection on MC 330 and MC 331 
cargo tanks inspect the delivery hose 
assembly and the piping system of the 
cargo tank under leakage test pressure 
utilizing the rejection criteria for cargo 
tanks unloading liquefied compressed 
gas. It should be noted that an operator 
should remove and replace damaged 
sections or correct defects discovered 
as provided in S6. 13.10. If any of the 
following is discovered, it is cause for 
rejection: 



a. No operator shall use a delivery 
hose assembly for liquefied com- 
pressed gas if it is determined that 
any of the following conditions 
exist: 

1 . Damage to the hose cover that 
exposes the reinforcement; 

2. If the wire braid reinforcement 
is kinked or flattened so as to 
permanently deform the wire 
braid; 

3. Soft spots when the hose is 
not under pressure, or any 
loose outer covering on the 
hose; 

4. Damaged, slipping, or exces- 
sively worn hose couplings; 

5. Loose or missing bolts or 
fastenings on the bolted hose 
coupling assembly. 

b. No operator can use a cargo tank 
with a piping system for unloading 
liquefied compressed gasses if any 
of the following conditions exist: 

1 . Any external leaks identifiable 
without the use of instruments; 

2. Bolting that is loose, missing, 
or severely corroded; 

3. Manual stop valves that will 
not actuate; 

4. Rubber hose flexible connec- 
tors with any of the following 
conditions: 

aa. damage to the hose cover 
that exposes the reinforce- 
ment; 

bb. if the wire braid rein- 
forcement is kinked or 
flattened so as to perma- 
nently deform the wire 
braid; 



23D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



requirements prescribed in the specifica- 
tion, that the cargo tank cannot be returned 
to hazardous material service. The cargo 
tank's specification plate shall be removed, 
obliterated, or covered in a secure manner. 
The inspector shall require that the cargo 
tank is calculated to identify the thickness 
of the material as required in S6. 13. 10.1 
and S6. 1.3. 10. 2 of this section. 

<:) MC cargo tanks constructed prior to Oc- 
tober I, 2003, require that the minimum 
thickness, minus the corrosion allowance 
as provided on the Manufacturer's Data 
Report. 

d) MC cargo tanks constructed after October 
I, 2003, require that the minimum thick- 
ness will be the value indicated on the 
specification plate of the cargo tank. If no 
corrosion allowance is indicated on the 
Manufacturer's Data Report, then the thick- 
ness of the cargo tank shall be the thickness 
of the material of construction indicated on 
the Manufacturer's Data Report, with no 
corrosion allowance. 



b) 



8o/7er and Pressure Vessel Code that are not 
stamped with the "U" Code Symbol Stamp 
must be constructed out of ASTM materi- 
als permitted in Part 1 78.345-2 of Title 49. 
These materials are as follows: 

1) ASTM A 569, 

2) ASTM A 570, 

3) ASTM A 572, 

4) ASTM A 607, 

5) ASTM A 622, 

6) ASTM A 656, and 

7) ASTM A 71 5. 

Aluminum alloys suitable for fusion weld- 
ing and conforming with the O, H 32, or 
H 34 temper of one of the following ASTM 
Specifications may be used for cargo tanks 
constructed in accordance with tbeASME 
Boiler and Pressure Vessel Code: 



S6.13.11.1 MINIMUM THICKNESS FOR 
400 SERIES CARGO TANKS 

400 series cargo tanks are required to satisfy the 
minimum thickness requirements as established 
in Part 1 78.320(a) of Title 49 for DOT 406 cargo 
tanks, Part 178.347.2 of Title 49 for DOT 407 
cargo tanks and Part 178.348.2 of Title 49 for 
DOT 412 cargo tanks. 



S6.13.1 1.2 DOT 406 CARGO TANKS 

a) It is required that all head, shell, bulkhead, 
and baffle materials used in the construc- 
tion of DOT 406 cargo tanks satisfy Parts A 
and B of Section II of the ASME Boiler and 
Pressure Vessel Code, except that the fol- 
lowing materials are authorized for cargo 
tanks constructed in accordance with ASMF 



1) ASTM B 209, Al 

2) ASTM B 209, Al 

3) ASTM B 209, Al 

4) ASTM B 209, Al 

5) ASTM B 209, Al 

6) ASTM B 209, Al 



loy 5052, 
loy 5086, 
loy 5154, 
loy 5254, 
loy 5454, and 
loy 5652. 



c) All heads, bulkheads, and baffles must be of 
O temper (annealed) or stronger temper. All 
shell material shall be of H 32, or H 34 tem- 
per, except that the lower ultimate strength 
temper should be used if the minimum 
shell thickness in the tables are increased in 
proportion to the lesser ultimate strength. 

d) Table S6.13.11.2-a specifics the mini- 
mum thickness requirements for heads or 



Z33 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Table S6.1 3.1 1.2 -a 
Minimum Thickness for Heads 



Materials 


Volume capacity in liter per mm of length (gallons per inch of length) 


''■' "W- 14(0.24) or less"'' '■;-"'■""- 


Over 14 to 23 (0.21 to 0.36) 


Over 23(0.36! 


MS 


HSLA ' 


AL 


MS 


HSLA 
SS 


AL 


':'. MS;:;. 


■" HSLA 

'. ' SS ."; 


AL 


Thickness, 
mm (in.) 


. 2 .54 . . .. 
"[(M6) ' - 


-'.'»■! 
(.100) 


.100 

14 061 


.115 

(2.92) 


.155 

(3.94) 


.173 
(4.39) 


'(3,28];';.. 


M 28) 


.187 

(4.75) 



Table S6.1 3.1 1.2-b 

Minimum Thickness for Shells, in. (mm) 



Cargo i ml motor vehicle raicd capacity Li liters (ga'lons) 


MS 


SS/HSLA 


i 

AL 


More than to at least 4,500 (0 to 1 7,000) 


2.54(0.100) 


2.54(0.100) 


3.84(0.151) 


More than 4,500 to at least 8.000 (17,000 to 30,300) 


2.92 (0.115) 


2.54(0.100) 


4.06(0.160) 


More than 8,000 to at least 14,000 (-30, 3'0() to 53,000) 


3.28(0.129) 


3.28(0.129) 


4.39(0.173) 


More than 14,000(53,000) 


3.63 (0.143) 


3.63 (0.143) 


4.75 (0.187) 


Note: The maximum distance between bulkhead, baffles, or ring sliffeners shall not exceed 1 ,525 mm (60 inches) 



bulkheads and baffles when used as tank 
reinforcement that is based on the volume 
capacity in gallons per I per mm (inch) of 
length for MC 406 cargo tanks constructed 
out of Mild Steel (MS), I ligh Strength Low 
Alloy Steel (HSLA), Austenitic Stainless 
Steel (SS), or Aluminum (Al .). 

Table S6.13.1 1 .2-b specifies the minimum 
thickness requirements for shell based on 
the cargo tank motor vehicle rated ca- 
pacity in gallons when ihe cargo lank is 
constructed out of Mild Steel (MS), High 
Strength Low Alloy Steel (HSLA), Austenitic 
Stainless Steel (SS), or Aluminum (AL). The 
thickness requirements in these tables are 
specified in decimal of a mm (inch) after 
forming. 



S6.1 3.1 1 .3 DOT 407 CARGO TANKS 

a) It is required that the type of materials used 
for DOT 407 cargo tanks, depending on the 
type of media being transferred be either 
Mild Steel (MS), High Strength Low Alloy 



Steel (HSLA), Austenitic Stainless Steel (SS), 
or Aluminum. 

b) The minimum required thickness of materi- 
als specified in Table S6. 13.1 1.3-a for DOT 
407 cargo tanks, when the minimum thick- 
ness requirements are based on the volume 
capacity in I iters I per sq mm (gallons) per 
square mm (inch) for the cargo tank's heads, 
or bulkheads and baffles, when these items 
are used for reinforcement purposes. All 
thicknesses are expressed in decimals of a 
mm (inch) after forming. 

c) The minimum required thickness of materi- 
als specified inTableS6.13.1 1 .3-bfor DOT 
407 cargo tanks, when the minimum thick- 
ness requirements are based on the volume 
capacity in Liters I per sq. mm (gallons) per 
square mm (inch) for the cargo tank shell. 
All thicknesses are expressed in decimals 
of a mm (inch) after forming. 



234 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Table S6.1 3.1 1.3-a 

Minimum Thickness for Heads (DOT 407), mm (in.) 



Volume capacity 
sq. mm 
(in gal./sq. in. I/) 


10(0.122) 
or less 


Over 10 
to 14 
(0.122 
to 0.1 71) 


Over 14 
to 18 

(0.171 
to 0.22) 


Over 1 8 
to 22 

(0.22 
to 0.268) 


Over 22 
to 26 
(0.268 
to 0.31 7) 


Over 26 
to 30 
(0.317 
to 0.365) 


Over 30 
(0.365) 

,'3.% 
(0.156) 


.. Thickness (MS) 


.' 2.54 : . 
1) UK" 


2.54 
iO.IOOi 


(0.115) 


3.28 ' 
10.129) 


3.28 : 
10.129) 


3.63 V 
(0.I 4 ',) 


Thickness 

(HSLA) 


2.54 
(0.100) 


2.54 
(0.100) 


2.92 
(0.115) 


3.28 

(0.129) 


3.28 
(0.129) 


3.63 

(0.143) 


3.96 
(0.156) 


Thk kiv.'ss iSSi 


2.54 
.0.100: 


2.54 
(0.100) 


2.92 
..0.I \5> 


l.JK 
O.l >M> 


I0.I29J 


3.63 
i0. NO 


l \3M\ v'"> v ! 
.0.1561 


Thickness (A) 


4.06 
(0.160) 


4.06 
(0.1 60) 


4.39 
(0.173) 


4.75 
(0.187) 


4.92 
(0.194) 


5.49 
(0.216) 


6.02 
(0.237) 



TableS6.13.11.3-b 

Minimum Thickness for Shells (DOT 407), mm (in.) 



Volume capacity 
in gal./sq. in. 
(l/sq. mm) 


10(0.122) 
or less 


Over 1 
to 14 
(0.122 
to 0.171) 


Over 14 
to 18 
(0.171 
to 0.22) 


Over 1 8 

to 22 
(0.22 
to 0.268) 


Over 22 
to 26 
(0.268 
to 0.31 7) 


Over 26 
to 30 

(0.317 
to 0.365) 


Over 30 

(0.365) 


Thic kness (MS) 


i0.10l.ii 


2.54 
.0.100. 


1.0. 1 1 


3.28 
(0.129) 


3.28 
;0.12''. 


3.63 
(0.143) 


/2/3.%,\; 
(0.1 56. 


Thickness 
(HSLA) 


2.54 
(0.100) 


2.54 
(0.100) 


2.92 
(0.115) 


3.28 

(0.129) 


3.28 
(0.129) 


3.63 
(0.143) 


3.96 
(0.156) 


rhicknes , (SS) 


2.54 
KI.I00) 


.' 7 .4 
(0.100) 


2.92 
.0.115. 


i.28 

' (6:1 29)> ;';"):; 


;2:. 
ui.l29i 


3.63 

(0.143) 


' 3296, 2.. ", '■/ 

>(o;T56> : ; :.;'■'■: 


Thickness (A) 


3.84 
(0.151) 


3.84 
(0.151) 


4.06 
(0.160) 


4.39 
(0.173) 


4.92 
(0.194) 


5.49 
(0.216) 


6.02 
(0.237) 



S6.1 3.1 1 .4 DOT 41 2 CARGO TANKS 

a) It is required that the type of materials used 
for DOT cargo tanks, depending on the type 
of media being transferred be either Mild 
Steel (MS), High Strength Low Alloy Steel 
(HSI A), Austenitic Stainless Steel (SS), or 
Aluminum. 

b) The minimum required thickness of materi- 
als specified inTable S6.1 3.1 1.4-a tor DOT 
412 cargo tanks, when the minimum thick- 
ness requirements are based on the volume 
capacity in liters per sq mm (gallons) per 
square mm (inch) for cargo tanks head, or 
bulkheads and baffles, when these items 



are used for reinforcement purposes. All 
thicknesses are expressed in decimals of 
mm (inch) after forming. 

The minimum required thickness of materi- 
als specified inTable S6. 13.1 1.4-bfor DOT 
41 2 cargo tanks, when the minimum thick- 
ness requirements are based on the volume 
capacity in liters per sq mm (gallons) per 
mm (inch) square for (he cargo tank's shell. 
All thicknesses are expressed in decimals 
of mm (inch) after forming. 



235 



NATIDNAL BOARD INSPECTION CODE • PART Z 



INSPECTION 









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236 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



2) Portable tanks shall be either hydrostati- 
cally or pneumatically tested with the 
formula 1.5 x design pressure + static 
head + 1 01 kPa (1 4.7 psi), if the tank is 
designed for external pressure. 

3) The portable tank shall be subjected to 
either a hydrostatic or pneumatic test at 
a test pressure of 1 .5 x the sum of the 
design pressure + the static head of lad- 
ing + 101 kPa (14.7 psi), if subjected to 
external vacuum. If the portable tank is 
constructed in accordance with ASME 
Section XII or Part UHT of ASME Sec- 
tion VIII, Div. 1, the test pressure shall 
be twice the design pressure. 

4) A pneumatic test may be used in lieu 
of a hydrostatic test if the following 
conditions are met: 

a. The owner-user has taken necessary 
precautions to ensure the safety of 
the inspection and test personnel; 

b. The pneumatic test pressure shall 
be reached gradually by increas- 
ing the test pressure to one-half of 
the test pressure. Once this pres- 
sure is reached, the test pressure 
will be increased in increments 
of approximately one-tenth of the 
test pressure until the required test 
pressure is reached; and 

c. When the test pressure is reached, 
the test pressure shall be reduced 
to at least four-fifths of the test pres- 
sure and held for a sufficient time 
to permit inspection of the portable 
tank. 



S6.14.4 EXCEPTIONAL INSPECTION 
AND TEST 

a) Exceptional inspection and test is neces- 
sary when a portable tank shows evidence 



of damage, corroded areas, or leakage, or 
other conditions that indicate a deficiency 
that could affect the integrity of the portable 
tank. 

b) The extent of the exceptional inspection 
and test shall depend on the amount of de- 
terioration of the portable tank. The excep- 
tional inspection and test shall include the 
requirements of S6.14.3 of this section. 

c) Pressure relief devices do not need to be 
included in this test unless there is reason to 
believe the relief device has been affected 
by damage or deterioration. 



S6.14.5 INTERNAL AND EXTERNAL 
INSPECTION PROCEDURE 

An internal and external inspection, when 
required, shall be performed by the owner- 
user. The inspection shall be conducted by the 
Inspector. This individual shall ensure that the 
portable tank is safe for continued transporta- 
tion service. The Inspector shall evaluate the re- 
sults of the inspection and report the applicable 
findings. The inspection shall include: 

a) Inspection of the shell for pitting, corrosion 
or abrasions, dents, distortions, defects in 
welds, or any other conditions, including 
leakage; 

b) Inspection of the piping, valves, and gas- 
kets for corroded areas, defects, and other 
conditions, including leakage that might 
make the portable tank unsafe for filling, 
discharge, or transportation; 

c) The tightening devices for manhole covers 
are operative, and there is no leakage at the 
manhole cover or gasket; 

d) Missing or loose bolts or nuts on any flanged 
connections including piping flanges, pres- 
sure relief device connections, or blank 
flanges. If any bolts are loose or missing, 
these shall be tightened or replaced; 



241 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



e) All emergency devices and valves to S6.14.6 
ensure that they are free from corrosion, 
distortion, and any damage or detects that 

could prevent the devices from operating 
as designed; 

f) All remote closures and self-closing stop 
valves shall be operated to demonstrate 
their proper operation; 

g) The required markings on the portable tanks 
shall be legible and in accordance with the 
applicable requirements of CFR Title 49, 

Part 1 78.3, and Part 1 80.605; and S6.1 4.6.1 



PRESSURE TEST PROCEDURES 
FOR SPECIFICATION 51, 57, 60, 
IM OR UN PORTABLE TANKS 



This section provides the requirements for 
pressure test procedures for Specification 51, 
57, 60, IM or UN Portable Tanks as provided 
in CFR Title 49, Part 180.605(h). Pressure test 
requirements for Specification 51, 57, 60, IM 
and UN Portable Tanks are identified in Table 
S6.13.6 of this subsection. 



h) The framework, supports, and the arrange- 
ments for lifting the portable tank to ensure a) 
that they are in a satisfactory condition. 



SPECIFICATION 57 PORTABLE 

TANKS 



Specification 57 portable tanks shall be 
leak tested by a minimum sustained air 
pressure of at least 21 kPa (3 psig) applied 
to the entire tank. 



Table S6.1 4.6 

Pressure Testing Requirements 



Specification 


Leak Test 


Hydrostatic 


Pneumatic 


Test Media 


Minimum Test Pressure 


' S\ arid 56/; 


!ijflij ; ™f-lli'ij';:|;*"i 


■■ ; -'xI 


;,*' C 


- Liquid or Air 


_> psi or .it Ir.isl l-l _' 

• times the design, pressure, 
"whichever isjgreater ; : 


51 and 56 used for 
transport refriger- 
ated liquefied gas 


X 


X 


X 


Liquid or Air 


90% of the Maximum 
Allowable Working 
Pressure 


5 I .Mid 5<; tnr ilu.' 
transport ot all other 
materials ■ 


— 


x\l- .■,/:. 


X 


Liquid or Air 


. 25% oi the Maximum ' 
; Allowable Wprkrhg;: '.- : 
■ .Pressure" 


57 


X 


— 


— 


— 


21 kPa (3 psi) to the 
entire tank 


,60. 


. „_,- ■-... . ,_ 


■'— : " '' ! VVafef or .'.." 
; other similar 

■'■■■ ,'| liquid j 


41 ; kPa K,() psig; 


UN nonrefrigerated 
gases 


— 


— 


— 


Water 


1 30% of Maximum 
Allowable Working 
Pressure 


UN refrigerated ■ :.'■ 
. : gases % 


\~ L ~\, ;.."■;'■':"■■. 


X 


'V'):^) 1 


Water oi Ah 


1 J times design pres ure 


IM refrigerated or 
nonrefrigerated 
liquefied gases 


■ ~~ 


X 


X 


Water or Air 


1 50% of the Maximum 
Allowable Working 
Pressure 



242 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



b) During each air pressure test, the entire 
surface of all joints, whether welded or 
threaded shall be coated with or immersed 
in a solution of soap and water, heavy oil, 
or other material suitable for the purpose 
of detecting leaks. 

c) The test pressure shall be held for a mini- 
mum of five minutes plus any additional 
time required to examine all portions of 
the portable tank. 

d) During the air test, the pressure relief de- 
vice may be removed or left in place. If 
the relief device is left in place during the 
test, the device's discharge opening shall 
be plugged. 

e) All closure fittings must be in place during 
the pressure test. 

f) If the portable tank is lagged or insulated, 
the lagging or insulation does not have to 
be removed if it is possible to maintain 
the required test pressure at a constant 
temperature with the portable tank discon- 
nected from the source of pressure. 



S6.1 4.6.2 SPECIFICATION 51 OR 56 
PORTABLE TANKS 

a) Specification 51 or 56 portable tanks shall 
be tested using either air or liquid. The mini- 
mum test pressure shall be at least 14 kPa 
(2 psig) or at least one and one-half times 
the maximum allowable working pressure 
(or re-rated pressure) of the portable tank. 
The greater test pressure shall be used. 

b) The leak testing of all refrigerated liquefied 
gas tanks shall be performed at 90% of the 
maximum allowable working pressure of 
the portable tank. 

c) Leak testing for all other portable tanks shall 
be at a test pressure of at least 25% of the 
maximum allowable working pressure of 
the portable tank. 



d) If the portable tank is hydrostatically tested, 
the enlire surface of Ihe portable tank shall 
be inspected for leaks. This includes all 
welded joints and threaded connections. 
The requirements below shall be followed 
for hydrostatic testing: 

1) The hydrostatic test pressure shall be 
held for a minimum of 5 minutes plus 
any additional time required to com- 
plete the inspection; 

2) The pressure relief device should be 
removed or left in place during the hy- 
drostatic test. If the relief device is left 
in place during the test, the device shall 
be isolated to avoid the relief device 
from discharging in accordance with 
the device manufacturer's recommen- 
dations; 

3) It is required for DOT 51 specification 
tanks that the relief valve be removed 
during the pressure test; and 

4) All closure fittings shall remain in place 
during the hydrostatic test. 

e) If the portable tank is pressure tested by air, 
during the test all surfaces of welded joints 
and thread connections of the portable tank 
shall be inspected for leaks and the follow- 
ing procedure shall be followed: 

1 ) All welded joints and threaded connec- 
tions shall be coated with or immersed 
in a solution of soap and water, or 
heavy oil or other material suitable for 
the purpose of detecting leaks; 

2) The air test pressure shall be held for a 
minimum of five minutes. This time pe- 
riod should be increased if so required 
by the Inspector; 

3) The pressure relief device should be 
removed or left in place during the 
air test. If the relief device is left in 
place during the test, the device shall 



243 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



be isolated to avoid the pressure relief 
device from discharging in accordance 
with the device manufacturer's recom- 
mendations; 

4) For Specification 51 portable tanks, the 
relief device shall be removed during 
the pressure test; and 

5) All closure fittings shall remain in place 
during the air test. 

If the portable tank is lagged or insulated 
and the pressure test performed is either 
hydrostatic or pneumatic, it is not neces- 
sary to remove the lagging or insulation for 
pressure testing provided the decay in test 
pressure can be measured at a constant 
temperature while the portable tank is dis- 
connected from the source of pressure. 



S6.1 4.6.3 SPECIFICATION 60 PORTABLE 

TANKS 

Specification 60 portable tanks shall be tested 
by completely filling the portable tank with 
water or other liquid having a similar viscosity. 
The test procedure shall include: 

a) The temperature of the liquid shall not 
exceed 37.7°C (1 00°F) during the test; 

b) The test pressure applied shall be at least 
413 kPa(60psig); 

c) The test pressure shall be maintained for a 
minimum of 1 minutes. This time period may 
be increased if required by the Inspector; 

d) During the 10-minute time period, the por- 
table tank shall be capable of maintai ning the 
test pressure with no evidence of leakage; 

e) All closures shall be left in place while the 
pressure test is being performed; 

f) The pressure gage shall be located at the 
tip of the vessel during the test; and 



Re-closing pressure relief devices must be 
removed from the tank and tested separately 
unless they can be tested while installed on 
the portable tank. 



S6.14.6.4 SPECIFICATION IM OR 
UN PORTABLE TANKS 

All Specification IM or UN portable tanks, 
except for UN portable tanks used for non- 
refrigerated and refrigerated liquefied gases, 
and all piping, valves, and accessories, except 
pressure relief devices shall be hydrostatically 
tested with water, or other liquid similar in 
density and viscosity as follows: 

a) All IM portable tanks used for non-refriger- 
ated and refrigerated liquid gases shall be hy- 
drostatically tested with water to a pressure 
of not less than 1 50% of the portable tanks 
maximum allowable working pressure; 

b) All UN portable tanks used for the trans- 
portation of non-refrigerated liquefied gases 
shall be hydrostatically tested, with water 
to a pressure not less than 130% of the 
portable tanks maximum allowable work- 
ing pressure. 

1) UN portable tanks used for the trans- 
portation of refrigerated gases should 
be tested by either hydrostatically or 
pneumatically using an inert gas to a 
pressure of not less than 1 .3 times the 
design pressure of the portable tank. 

2) If the portable tank is subjected to the 
pneumatic test method, the owner-user 
shall take necessary precautions for the 
safety of the inspection and test person- 
nel. 

3) The pneumatic test pressure shall be 
reached gradually by increasing the test 
pressure to one-half of the test pressure. 
Once this pressure is reached, the test 
pressure will be increased in incre- 
ments of approximately one-tenth of 



244 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



cular in cross section and shall have heads 
of an approved design, with all fittings, i.e., 
couplings, nozzles, etc., located in the heads 
of the tank. 



S6.15.1 SPECIAL PROVISIONS FOR 

TON TANKS 

49 CFR, Section 179.300 has specific criteria 
for ton tanks that shall be met to satisfy DOT 
Specification 106A and 110A.The limitations 
are as follows: 

a) Ton tanks shall have a water containing ca- 
pacity of at least 1 500 pounds (0.68 tonne), 
but in no case can the water containing ca- 
pacity of the ton tank exceed 2600 pounds 
(1.18 tonne); 

b) Ton tanks shall not be insulated; 

c) Thickness of plates for DOT Specification's 
106A and 110A ton tanks shall be in ac- 
cordance with Table S6.1 5.1 -a; 

d) The maximum carbon content for carbon 
steel used in the fabrication of ton tanks 
shall not exceed 0.31 percent; 

e) Permitted materials can be either an ASME, 
SA material, or an ASTM Material permitted 
by Table S6.1 5.1 -b; 

f) DOT Specification 106A ton tanks shall 
only use forged-welded heads, convex to 
pressure. The forged-welded heads shall 
be torispherical with an inside radius not 
greater than the inside diameter of the shell. 
The heads shall be one piece, hot formed in 
one heat so as to provide a straight flange 
at least 4 inches (1 00 mm) long. The heads 
must have a snug fit into the shell; 

g) DOT Specification 110A ton tanks shall 
only use fusion-welded heads formed con- 
cave to pressure. The fusion-welded heads 
shall be an ellipsoid of 2:1 ratio and shall 
be of one piece, hot formed in one heat so 



as to provide a straight flange at least 1 -1/2 
inches (38 mm) long; 

h) All longitudinal welded joints on DOT 
Specification 106Aand DOT Specification 
1 1 0A ton tanks shall be a fusion weld. DOT 
Specification 106A ton tank head to shell 
attachments shall be a forged-welded joint. s 
DOT Specification 1 10A ton tank head to 
shell attachments shall be a fusion weld; 

i) Postweld heat treatment is required after 
welding for all DOT Specification 106A 
and Specification 1 10A ton tanks; 

j) DOT Specification 1 06A and DOT Speci- 
fication 1 10A ton tanks shall be of such a 
design as to afford maximum protection 
to any fitting or attachment to the head, 
including loading and unloading valves. 
The protection housing 3 shall not project 
beyond the end of the ton tanks and shall 
be securely fastened to the tank head; 

k) If applicable, siphon pipes and their cou- 
plings on the; inside of the ton tank's head 
and lugs on the outside of the tank head for 
attaching valve protection housing shall be 
fusion welded prior to performing postweld 
heat treatment; 

I) DOT Specification 106A and DOT Speci- 
fication 1 1 0A ton tanks are required to be 
equipped with one or more approved types 
of pressure relief devices. The device shall 
be made out of metal and the pressure 
relief devices shall not be subject to rapid 
deterioration by the lading. The device's 
inlet fitting to the tank shall be a screw-type 
fitting and installed or attached directly into 
the ton tank's head or attached to the head 
by other approved methods. For thread 
connections, the following shall apply: 

1 ) The threaded connections for all open- 
ings shall be in compliance with the 
National Gas Taper Threads (NGT); 



5 The forged-welded joint shall be thoroughly hammered or 
rolled to ensure a sound weld. 



24V 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



TabieS6.15.1-a 

Thick ness of Plates and Safety Valve Requirements 



DOT S»| ( oi jfjiafi?jn 


106A500-X 


106A800-X 


110A500-VV 


5J0MMMV 


1I0A800-W 


110A1000-W 


Minimum required 


None 


None 


8.62 


10.34 


13.8 


17.2 


bursting pressure, MPa 


Specified 


Specified 


(1,250) 


(1,500) 


(2,000) 


(2,500) 


(psig) 






:p.$:?!?JS-K'X& 








Minimum thickness 


10mm 


1 7mm 


10mm 


10mm 


12mm 


15mm 


shell, inches (mm), 


(13/32) 


(11/16) 


(11/32) 


(3/8) 


(15/32) 


(19/32) 


Test Pressure (See CFR 


3.45 


5.52 


3.45 


4.41 


5.52 


6.89 


179.300-15), MPa 


(500) 


(800) 


(500) 


(600) 


(800) 


(1,000) 


(psig) 














Start-to-discharge, 


2.59 


4.14 


"2.59 


3.10 


4.14 


4.83 


or burst pressure 


(375) 


(600) 


(375) 


(450) 


(600) 


(700) 


(maximum MPa (psig)) 















Table S6.1 5.1 -b 

Acceptabl e Ma terials with Acceptable Tensile Strength and Elongation Requirements 



Minimum Tensile S?reiii;Ua Mfci (psi) 

in the v^'dt,') condition. 



Minimum ricwgatirn in 50 siitn (2 in. i 
((Kvrwst) in me s,w.>k\'! ox-iJiiioH. 



/Vijteriis! Sp^t-iff'-atii-i 


r/vese vjlut \ cire to />e used in the 
i A 's/i,','? cjlcuLnii'in<. 


r/)f>e \ ,)/(;«'> ,'.'f to !x j us<? 
fh'^i^ii i ,ik:iiljti<.>n? 


din 'the . 


ASTM A 240 type 304 


75,000(517) 


25 


ASTMA240t\p*'U)4l 


:7d,d0p(483) ■' " 


■■'"'■■' i ; 25;" : . 


ASTM A 240 type 31 6 


75,000(517) 


25 


ASTM A 240 type i16i 


;' 70,000(483) 


"^"15' 


ASTM A 240 type 521 


75,000(517) 


25 


asima:;-;-, (..„. \ 


".":■■■■■'„ :45/00d : (3i0) ; :, ..j. : .,.' ; *'' : ,' ; '!':■■.;■.,. 


"'■^' :/ 29\. '.;■■"'■- 


ASTM A 285 Cr. B 


50,000 (345) 


20 




ASTM A 285 Gr. C 


':\/',:-{y-- { ] . 55,po0 (380) ; : v 


20 


ASTM A 515 Gr. 65 


65,000 (448) 


20 


ASTM A 515 Gr. "0 


V'-V-'-. '-,"■■ "::7O,OO0'(483.y'.'"^V : 


.V. :20 v '" r : 


ASTM A 51 6 Gr. 70 


70,000 (483) 


20 



248 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



2) Pressure relief devices shall be set for 
start-to-discharge and rupture discs shall 
burst at a pressure not exceeding the 
pressure identified in Table S6.1 5.1 -a. 



f) Distortions; or 

g) Any other conditions that might make the 
ton tank unsafe for transportation. 



m) Fusible plugs if used shall be required to 
relieve the pressure from the lank at a tem- 
perature not exceeding 79°C (1 75°F) and 
shall be vapor tight at a temperature not 
exceeding 54°C(130°F). 



S6.15.2 VISUAL INSPECTION OF 
TON TANKS 

Without any regard to any other periodic in- 
spection and test requirements, a ton tank shall 
be visually inspected for evidence of any: 

a) Defects in welds; 

b) Abrasions; 

c) Corrosion; 

d) Cracks; 

e) Dents; 



S6.1 5.3 INSPECTION AND TESTS OF 
DOT SPECIFICATION 106A 
AND DOT SPECIFICATION 110A 

TON TANKS 

Each ton tank shall be retested by subjecting 
the ton tank to a hydrostatic test in accordance 
with Table S6.15.3. The hydrostatic test shall 
include an evaluation of the tank's permanent 
expansion. As a minimum the hydrostatic test 
and the expansion procedure shall include: 

a) The hydrostatic test pressure shall be main- 
tained for a minimum of 30 seconds. This 
time period may be extended as long as 
necessary to secure complete expansion 
of the ton tank. 

b) The pressure gage used for the hydrostatic 
test shall be accurate within one percent of 



Table S6.1 5.3 
Ton Tank Pern 


idic Inspect 


on and Test 


Frequencies 








RHfst interval, wars 


Minimum Retest 
Pressure, MPa (psig) 


Pressure Relief Valve 

Pressure, MPa (psig.) 


DOT 
Specification 


Tank 


Pressure 
Relief o 
Device 


Tank 

Hydrostatic 

Expansion 


Tank Air 
Test 


Slar(-lo- Vapor 
Discharge 'fight 


106A500 






'RjS:y;f : : [f^^-^W^^ 


500 (3.45) 


100(0.69) 


csu.iM! ion i:\07i 


1 06A500X 






■~y 


500 (3.45) 


100(0.69) 


rsu.SM, ;iK)l_'.0-, 


106A800 






■ : £> J^yy::::v >::;v;v::;!: :: : 


800(5.52) 


100(0.69) 


600(4 14;) ; 4801 ! i 1 ! 


106A800X 






iibji: -: Hii'^' ^> : V: 


800(5.52) 


100(0.69) 


": : &d£!(4.T ; 4) : : 1 = 480034 ) : (i 


106A800NCI 






O 


800 (5.52) 


100(0.69) 


1.00144-1. 48()i;..ili 


1 1 0A500-W 






-) 


500 (3.45) 


100(0.69) 


'.75 (.2. 39' : IOOO.iT 1 ! 


110A600-W 






^■:0^0y^:0M^:^ 


600(4.41) 


100(0.69) 


50(n;.4 c .i \ ihinj.a.'-.i 


110A800-W 






? 


800 (5.52) 


100(0.69) 


(,()()(4.l4i ■ 4S0 il.il: 


110A1000-W 






') 


1,000(6.89) 


100(0.69) 


_ 50(5.l7i 600(4.4 1: 



249 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



the range of the pressure gage. The accuracy 
of the pressure gage shall be verified prior 
to performing the hydrostatic test. 

c) The expansion test procedure shall include 
the following requirements: 

1) The expansion shall be recorded in 
cubic cm; 

2) Permanent volumetric expansion shall 
not exceed 1 0% of the total volumetric 
expansion at the test pressure; and 

3) The expansion gage shall be accurate 
within one percent of the hydrostatic 
test pressure. 

d) The ton tank shall not show any signs of 
leakage or stress during the hydrostatic and 
expansion test. 

e) The retest may be made at any time during 
the calendar year the retest falls due. 



S6.15.3.2 PRESSURE RELIEF DEVICE 
TESTING 

All pressure relief devices shall be retested by 
air or gas for the start-to-discharge and vapor 
tightness requirements at frequencies and pres- 
sures specified in Table S6.15.3. 



S6.15.3.3 RUPTURE DISCS AND FUSIBLE 
PLUGS 

All rupture discs required by S6.15.1 (l)(2) and 
fusible plugs required by S6.15.1(m) shall be 
removed from the ton tank and inspected. The 
inspection shall include but not limited to the 
following: 

a) All rupture discs shall be inspected for 
corrosion, leakage, and manufacturer toler- 
ances; 

b) All fusible plugs shall be inspected for cor- 
rosion, loose, or deteriorated temperature 
sensitive materials; 



S6.1 5.3.1 AIR TESTS 

a) All specification DOT 1 06A and DOT 1 1 0A 
ton tanks, in addition to the hydrostatic 
test shall be subjected to an air test at fre- 
quencies and pressures specified in Table 
S6.15.3. 

b) The air test shall be under positive control 
to ensure safety to all inspection and test 
personnel. 

c) Any leakage observed will require the ton 
tank to be repaired and retested prior to 
placing the ton tank back into service. 



c) Any indication specified in (a) and (b) above 
will require the rupture disc or fusible plug 
to be replaced with devices specified in 
S6.1 5.1 (l)(2) and S6.1 5.1 (m) of this section. 



S6.1 5.3.4 SUCCESSFUL COMPLETION OF 
THE PERIODIC RETESTING 

If the results of the periodic retest are successful, 
the ton tank shall be plainly and permanently 
stamped on one head or chime of each ton 
tank. The stamping shall include: 

a) The month and year of the test followed by 
a "V", and 

b) Dates of previous tests and all prescribed 
markings shall not be removed. Previous 
dates and markings on the ton tank's head 
or chime shall be legible. 



25D 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S6.15.3.5 EXEMPTIONS TO PERIODIC 
HYDROSTATIC RETESTING 

Ton tanks that satisfy DOT 1 06A and DOT 1 1 0A 
that are used exclusively for transporting fluori- 
nated hydrocarbons and mixtures thereof, and 
are free from corroding components related to 
the ton tank may be exempted from the periodic 
hydrostatic retest if: 

a) The ton tank is given a complete internal 
and external visual inspection of all heads, 
shells, nozzles, couplings, pressure relief 
devices, i.e. pressure relief valves and rup- 
ture discs and fusible plugs for deterioration 
and leakage. 

b) The visual internal and external inspec- 
tion is performed by qualified personnel, 
i.e., registered inspector, employee of the 
owner-user, etc. 



S6.1 5.3.6 RECORD OF RETEST 
INSPECTION 

The owner or the person performing the re- 
quired pressure test and visual inspection is 
required to retain a written record of the results 
as long as the ton tank is in service. The written 
report shall identify the following: 

a) Date of the test and inspection; 

b) DOT Specification Number of the ton 
tank; 

c) Ton tank identification: registered symbol 
and serial number, date of manufacture, 
and ownership symbol; 

d) Type of protective coating, i.e., painting, 
etc.; 

e) Statement as to the need for refinishing or 
recoating the ton tank; 

f) Conditions checked for: 
1 ) leakage; 



2) corrosion; 

3) gouges; 

4) dents or dings; 

5) broken or damaged chimes, or protec- 
tive rings; 

6) fire damage; 

7) internal conditions; 

8) test pressure; and 

9) the written report shall also identify the 
results of the test: 

a. disposition of the tank, i.e., returned 
to service, returned to the manufac- 
turer for repair, or scrapped; and 

b. Identification of the person per- 
forming the retest or inspection. 

S6.15.4 STAMPING REQUIREMENTS 

OF DOT106AAND DOT110A 

TON TANKS 

To identify compliance with CFR 179.300-1 
each DOT 1 06A and DOT 1 1 0A ton tank shall 
be plainly and permanently stamped with let- 
ters and figures 3/8 of an inch high on valve 
end chime of the ton tank's head. The minimum 
requirements for the stamping are as follows: 

a) DOT Specification Number; 

b) Material and cladding material if any. This 
information shall be stamped directly be- 
low the DOT Specification Number; 

<:) Owner's or builder's identifying symbol 
and serial number. This information shall 
be stamped directly below the material 
identification stamping. The owner's or 
builder's symbol shall be registered with 
the Bureau of Explosions (duplications are 
not authorized); 



25 1 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



d) Inspector's official mark. This information 
shall be stamped directly below the owner's 
or builder's symbol; 

e) Date of the original ton tank test (month 
and year). Provisions should be made 
that subsequent tests may easily be added 
thereto; 

f) Water capacity of the ton tank in Kilograms 
(pounds); 

g) A duplicate of the stamping that satisfies 
(a) through (f) should be used if the plate is 
made of brass and is permanently attached 
to the ton tank's head. 



A07 S6.16 



DEFINITIONS 



These Definitions shall be used in conjunction 
with those of Section 9 of the N'BIC. Where 
conflicts between the two arise, those listed 
below shall prevail. 

Approval — A written authorization, includ- 
ing a competent authority approval from the 
Associate Administrator or other designated 
department official, to perform a function for 
which prior authorization by the Associate 
Administrator is required. 

Approval Agency — An organization or a per- 
son designated by the DOT to certify packaging 
as having been designed, manufactured, tested, 
modified, marked, or maintained in compli- 
ance with applicable DOT regulations. 

Approved — Approval issued or recognized by 
the department unless otherwise specifically 
indicated. 

Appurtenance — Any attachment to a cargo 
tank that has no lading retention or containment 
function and provides no structural support to 
the cargo tank. 

Associate Administrator -- The Associate Admin- 
istrator for Hazardous Materials Safety, Research, 
and Special Programs Administration. 



Atmospheric Gas — Air, nitrogen, oxygen, 
argon, krypton, neon, and xenon. 

Attachments - Structural Members means 
the suspension sub-frame, accident protection 
structures, external circumferential reinforce- 
ments, support framing, and kingpin sub-frame 
(upper coupling). 

Attachments Light Weight — Welded to a 
cargo tank wall such as a conduit clip, brake 
line clip, skirting structure, lamp mounting 
bracing, or placard holder. 

Authorized Inspector (A!) — An inspector 
regularly employed by an ASME-accredited 
Authorized Inspection Agency (AIA) who has 
been qualified to ASME developed criteria, to 
perform inspections under the rules of any Ju- 
risdiction that has adopted the ASMF Code. 

Baffle — A nonliquid-tight transverse partition 
device that deflects, checks, or regulates fluid 
motion in a tank. 

Bar— 1 BAR= 100 kPa (14.5 psi) 

Bottle — An inner packaging having a neck of 
relatively smaller cross section than the body 
and an opening capable of holding a closure 
for retention of the contents. 

Bottom Shell —That portion of a tank car sur- 
face, excluding the head ends of the tank car 
that lies within two feet, measured circumfer- 
entially, of the bottom longitudinal center line 
of the tank car tank. 

Bulk Packaging — A packaging other than the 
vessel or a barge, including a transport vehicle 
or freight container, in which hazardous mate- 
rials are loaded with no intermediate form of 
containment and which has: 

a) A maximum capacity greater than 450L 
(1 1 9 gallons) as a receptacle for a liquid; 

b) A maximum net mass greater than 400 kg 
(882 pounds) and a maximum capacity 



252 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Poisonous Gas — A material that is a gas at 
20°C (68°F) or less and a pressure of 1 01 .3 kPa 
(14.7 psia) [a material that has a boiling point 
of 20°C (68°F) or less at 1 01 .3 kPa (1 4.7 psia] 
and which: 

a) Is known to be so toxic to humans as to 
pose a hazard to health during transporta- 
tion; or 

b) In the absence of adequate data on human 
toxicity, is presumed to be toxic to humans 
because when tested on laboratory animals 
it has an LC50. 

Poisonous Material — A material, other than a 
gas, which is known to be so toxic to humans as 
to afford a hazard to health during transporta- 
tion, or which in the absence of adequate data 
on human toxicity. 

Portable Tanks — A bulk packaging (except 
cylinder having a water capacity of 1000 
pounds or less) designated primarily to be 
loaded onto, or on, or temporarily attached to 
a transport vehicle or ship and equipped with 
skids, mountings, or accessories to facilitate 
handling of the tank by mechanical means. It 
does not include a cargo tank, tank car, multi- 
unit tank car tanks, or trailers carrying 3AX, 
3AAX, or 3T cylinders. 

psi — Pounds per square inch. 

psia — Pounds per square inch absolute. 

psig — Pounds per square inch gage. 

Qualified Inspector — An inspector regularly 
employed by an ASME Qualified Organiza- 
tion (QIC)) who has been qualified to ASME 
developed criteria by a written examination, 
to perfom inspections under the rules of any 
jurisdiction that has adopted the ASME Code. 
The Ql shall not be in the employ of the manu- 
facturer. See ASME XII, TC-41 0. 

Rail Car — A car designed to carry freight or 
nonpassenger personnel by rail, and includes a 



box car, flat car, gondola car, hopper car, tank 
car, and occupied caboose. 

Rebarrelling — Replacing more than 50% of 
the combined shell and head material of a 
cargo tank. 

Receptacle — A containment vessel for receiv- 
ing and holding materials, including any means 
of closing. 

Registered Inspector (Rl) — A person regis- 
tered with the department in accordance with 
Subpart F of Part 107 of 49 CFR who has the 
knowledge and ability to determine whether a 
cargo tank conforms with the applicable DOT 
specification. In addition, Registered Inspector 
means a person who meets, at a minimum, any 
one of the following: 

a) Has an engineering degree and one year of 
work experience; 

b) Has an associate degree in engineering and 
two years of work experience; 

c) Has a high school diploma or General 
Equivalency Diploma and three years work 
experience; or 



d) Has at least three years experience; perform- 
ing the duties of a Registered Inspector by 
September 1 , 1 991 , and was registered 
the DOT by December 31,1 995. 



wi 



th 



Repair — Any welding on a cargo tank wall 
done to return a cargo tank or a cargo tank mo- 
tor vehicle to its orginial design and construc- 
tion specification, or to a condition prescribed 
for a later equivalent specification in effect at 
the time of the repair. Excluded from this cat- 
egory are the following: 

a) A change to motor vehicle equipment 
such as lights, truck, or tractor power train 
components. Steering and brake systems, 
suspension parts, and changes to appurte- 
nances, such as fender attachments, light- 
ing brackets, ladder brackets; 



Z5V 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



b) Replacement of components such as valves, 
vents, and fittings with a component of a 
similar design and of the same size; and 

c) Replacement of an appurtenance by weld- 
ing to a mounting pad. 

Replacement of a Barrel — To replace the ex- 
isting tank on a motor vehicle chassis with an 
unused (new) tank. 

SCF (standard cubic foot) — One cubic foot of 
gas measured at 60°F, and 14.7 psia. 

Single Packaging — A nonbulk packaging other 
than a combination packaging. 

Solid — A material that is not a gas or liquid. 

Solution — Any homogenous liquid mixture of 
two or more chemical compounds or elements 
that will not undergo any segregation under 
conditions normal to transportation. 

Specification Packaging — A packaging con- 
forming to one of the specifications or standards 
for packaging in Part 178 or Part 179 of Title 
49. 

Strong Outside Container — The outermost 
enclosure that provides protection against the 
unintentional release of its contents under con- 
ditions normally incident to transportation. 

Tanks — A container, consisting of a shell 
and heads that form the pressure vessel hav- 
ing opening designed to accept pressure tight 
fittings or closure, but excludes any appurte- 
nances, reinforcements, fittings, or closures. 

Test Pressure —The pressure to which a tank is 
subjected to determine structural integrity. 

Top Shell — The tank car surface, excluding the 
head ends and bottom shell of the tank car. 



Transport Vehicle — A cargo-car-carrying 
vehicle such as an automobile, van, tractor, 
truck, semi trailer, tank car, or rail car used for 
the transportation of cargo by any mode. Each 
cargo-carrying body (trailer, rail car, etc.) is a 
separate transport vehicle. 

UFC — Uniform Freight Classification. 

UN — United Nations. 

UN Portable Tank — An intermodal tank having 
a capacity of more than 450L (1 1 8.9 gallons). 
It includes a shell fitted with service equipment 
and structural equipment, including stabilizing 
members external to the shell and skids, mount- 
ings or accessories to facilitate mechanical 
handling. A UN portable tank must be capable 
of being filled and discharged without the 
removal of its structural equipment and must 
be capable of being lifted when full. Cargo 
tanks, rail tank car tanks, nonmetallic tanks, 
nonspecification tanks, bulk bins, and IBC's 
and packaging made to cylinder specifications 
are not UN portable tanks. 

UN Recommendation — The UN Recom- 
mendations on the Transport of Dangerous 
Goods. 

UN Standard Packaging — A conforming to 
standards in the UN Recommendations. 

Vessel - Includes every description of water- 
craft, used or capable of being used, as a means 
of transportation on the water. 

Viscous Liquid — A liquid material that has 
a measured viscosity in excess of 2500 cen- 
tistokes at 25°C (77°F), when determined in 
accordance with the procedures specified in 
ASTM Method D 445-72 "Kinematic Viscosity 
of Transparent and Opaque Liquids (and the 
Calculation of Dynamic Viscosity)," or ASTM 
Method D 1200-70 "Viscosity of Paints, Var- 
nishes, and Lacquers by Ford Viscosity Cup." 



25B 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



SUPPLEMENT 7 

INSPECTION OF PRESSURE 
VESSELS IN LIQUEFIED 
PETROLEUM CAS (LPG) SERVICE 



S7.1 



SCOPE 



a) Pressure vessels designed for storing LPG 
can be stationary or can be mounted on 
skids. LPG is generally considered to be 
non-corrosive to the interior of the ves- 
sel. This part is provided for guidance of 
a general nature for the owner, user, or 
jurisdictional authority. There may be oc- 
casions where more detailed procedures 
will be required such as changing from 

A07 one gas service to another (i.e., anhydrous 
ammonia to LPG). 

b) The application of this Supplement to un- 
derground vessels will only be necessary 
when evidence of structural damage to the 
vessel has been observed, leakage has been 
determined, or the tank has been dug up, 
and is to be reinstalled. 



6) National Board and/or jurisdictional 
registration number, if required. 

b) The vessel should be sufficiently cleaned 
to allow for visual inspection. 



S7.3 INSERVICE INSPECTION FOR 

VESSELS IN LP GAS SERVICE 

The type of inspection given to pressure vessels 
should take into consideration the condition 
of the vessel and the environment in which it 
operates. The inspection may be external or 
internal, and use a variety of nondestructive 
examination methods. Where there is no reason 
to suspect an unsafe condition or where there 
are no inspection openings, internal inspections 
need not be performed. When service condi- 
tions change from one service to another, such 
as ammonia to LPG, an internal inspection may 
be required. The external inspection may be 
performed when the vessel is pressurized or 
depressurized, but shall provide the necessary 
information that the essential sections of the 
vessel are of a condition to operate. 



A07 



S7.2 



PRE-INSPECTION ACTIVITIES 



a) A review of the known history of the pres- 
sure vessel should be performed. This 
should include a review of information, 
such as: 

1) Operating conditions; 

A07 2) Historical contents of the vessel; 

3) Results of any previous inspection; 

4) Current jurisdictional inspection certifi- 
cate, if required; 

5) ASME Code symbol stamping or mark 
of code of construction, if required; 
and 



S7.3.1 NONDESTRUCTIVE 

EXAMINATION (NDE) 

Listed below are a variety of methods that may 
be employed to assess the condition of the 
pressure vessel. These examination methods 
should be implemented by experienced and 
qualified individuals. Generally, some form of 
surface preparation will be required prior to 
the use of these examination methods: visual, 
magnetic particle, liquid penetrant, ultrasonic, 
radiography, radioscopy, eddy current, metal- 
lographic examination, and acoustic emission. 
When there is doubt as to the extent of a defect 
or detrimental condition found in a pressure 
vessel, additional NDE may be required. 



259 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



S7.4 



EXTERNAL INSPECTION 



All parts of ihe vessel shall be inspected tor 
corrosion, distortion, cracking, or other condi- 
tions as described in this Section. In addition, 
the following should be reviewed, where ap- 
plicable: 

A07 a) Insulation or Coating 

If the insulation or coating is in good con- 
dition and there is no reason to suspect an 
unsafe condition behind it, then it is not 
necessary to remove the insulation or coat- 
ing in order to inspect the vessel. However, 
it may be advisable to remove a small por- 
tion of the insulation or coating in order to 
determine its condition and the condition 
of the vessel surface. 

A07 b) Evidence of Leakage 

Any leakage of vapor or liquid shall be 
investigated. Leakage coming from behind 
insulation or coating, supports, or evidence 
of past leakage shall be thoroughly investi- 
gated by removing any insulation necessary 
until the source is established. 



open to provide visual evidence of leak- 
age as well as to prevent pressure build 
up between the vessel and the reinforcing 
plate. Accessible flange faces should be 
examined for distortion. It is not intended 
that flanges or other connections be opened 
unless there is evidence of corrosion to 
justify opening the connection. 

Fire Damage 

Pressure vessels shall be carefully inspected 
for evidence of fire damage. The extent of 
fire damage determines the repair that is 
necessary, if any. (See S7.7). 



S7.5 



INTERNAL INSPECTION 



When there is a reason to suspect an unsafe 
condition, the suspect parts of the vessel shall 
be inspected and evaluated. 

The vessel shall be prepared and determined to A07 
be gas free and suitable for human entry prior 
to internal inspection. (See 2.3.4). 



c) Structural Attachments 

The pressure vessel mountings should be 
checked for adequate allowance for expan- 
sion and contraction, such as provided by 
slotted bolt holes or un-obstructed saddle 
mountings. Attachments of legs, saddles, 
skirts, or other supports should be exam- 
ined for distortion or cracks at welds. 

d) Vessel Connections 

Components that are exterior to the vessel 
and are accessible without disassembly 
shall be inspected as described in this 
paragraph. Manholes, reinforcing plates, 
A07 nozzles, couplings, or other connections 
shall be examined for cracks, deformation, 
or other defects. Bolts or nuts should be 
examined for corrosion or defects. Weep 
holes in reinforcing plates shall remain 



S7.6 



LEAKS 



Leakage is unacceptable. When leaks are iden- A07 
tified, the vessel shall be removed from service 
until repaired by a qualified repair organization 
or permanently removed from service. 



S7.7 



FIRE DAMAGE 



Vessels in which bulging exceeds the lim- 
its of S7.8.3 or distortion that exceeds the 
limits of the original code of construction 
(e.g., Section VIM, Div. 1 of the ASMF Boiler 
and PressureVessel Code) shall be removed 
from service until repaired by a qualified re- 
pair organization or permanently removed 
from service. 



A07 



26D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



b) Common evidence of exposure to fire is: S7.8 



ACCEPTANCE CRITERIA 



1 ) charring or burning of the paint or other 
protective coat; 

2) burning or scarring of the metal; 

3) distortion; or 

4) burning or melting of the valves. 

c) A pressure vessel that has been subjected 
to the action of fire shall be removed from 
service until it has been properly evaluated. 
The general intent of this requirement is to 
remove from service pressure vessels which 
have been subject to the action of fire that 
has changed the metallurgical structure or 
the strength properties of the steel. Visual 
A07 examination with emphasis given to the 
condition of the protective coating can be 
used to evaluate exposure from a fire. This 
is normally determined by visual exami- 
nation as described above with particular 
emphasis given to the condition of the 
protective coating. If there is evidence that 
the protective coating has been burned off 
any portion of the pressure vessel surface, 
or if the pressure vessel is burned, warped, 
or distorted, it is assumed that the pressure 
vessel has been overheated. If, however, 
the protective coating is only smudged, 
discolored, or blistered, and is found by 
examination to be intact underneath, the 
pressure vessel shall not be considered af- 
fected within the scope of this requirement. 
Vessels that have been involved in a fire 
and show no distortion shall be requalified 
for continued service by retesting using the 
hydrostatic test procedure applicable at the 
time of original fabrication. 

A07 d) Subject to the acceptance of the Jurisdic- 
tion and the Inspector, alternate methods 
of pressure testing may be used. 



The acceptance criteria for LPG vessels is based 
on successfully passing inspections without 
showing conditions beyond the limits shown 
below. 



S7.8.1 



CRACKS 



Cracks in the pressure boundary (heads, shells, A07 
welds) are unacceptable. When a crack is iden- 
tified, the vessel shall be removed from service 
until the crack is repaired by a qualified repair 
organization or permanently retired from ser- 
vice. (See Part 3, Repairs and Alterations). 



S7.8.2 



DENTS 



a) Shells 

The maximum mean dent diameter in shells 
shall not exceed 10% of the shell diameter, 
and the maximum depth of the dent shall 
not exceed 1 0% of the mean dent diameter. 
The mean dent diameter is defined as the 
average of the maximum dent diameter and 
the minimum dent diameter. If any portion 
of the dent is closer to a weld than 5% of 
the shell diameter, the dent shall be treated 
as a dent in a weld area, sec (b) below. 

b) Welds 

The maximum mean dent diameter on 
welds (i.e., part of the deformation includes 
a weld) shall not exceed 10% of the shell 
diameter. The maximum depth shall not 
exceed one twentieth of the mean dent 
diameter. 

c) Heads 

The maximum mean dent diameter on 
heads shall not exceed 10% of the shell 
diameter. The maximum depth shall not 
exceed one twentieth of the mean dent 
diameter. The use of a template may be 
required to measure dents on heads. 



26 1 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



d) When dents are identified which exceed 
the limits set forth in these paragraphs, the 
vessel shall be removed from service until 
the dents are repaired by a qualified repair 
organization or permanently retired from 
service. 



S7.8.5 



CORROSION 



S7.8.3 



BULGES 



a) Shells 

If a bulge is suspected, the circumference 
shall be measured at the suspect location 
and several places remote from the suspect 
location. The variation between measure- 
ments shall not exceed 1%. 

b) Heads 

1) If a bulge is suspected, the radius of 
curvature shall be measured by the use 
of templates. At any point the radius 
of curvature shall not exceed 1 .25% of 
the diameter for the specified shape of 
the head. 

2) When bulges are identified that exceed 
the limits set forth in these paragraphs, 
the vessel shall be removed from ser- 
vice until the bulges are repaired by a 
qualified repair organization or perma- 
nently retired from service. 



S7.8.4 CUTS OR GOUGES 

When a cut or a gouge exceeds 1 /4 of the th ick- 
ness of the vessel, the vessel shall be removed 
from service until it is repaired by a qualified 
repair organization or permanently removed 
from service. 



a) Line and Crevice Corrosion 

For line and crevice corrosion, the depth 
of the corrosion shall not exceed 1/4 of the 
original wall thickness. 

b) Isolated Pitting 

Isolated pits may be disregarded provided 
that: 

1) Their depth is not more than one-half 
the required thickness of the pressure 
vessel wall (exclusive of corrosion al- 
lowance); 

2) The total area of the pits does not ex- 
ceed 7 sq. in. (4500 sq. mm) within any 
8 in. (200 mm) diameter circle; and 

3) The sum of their dimensions along any 
straight line within this circle does not 
exceed 2 in. (50 mm). 

c) General Corrosion 

For a corroded area of considerable size, 
the thickness along the most critical plane 
of such area may be averaged over a length 
not exceeding 20 in. (500 mm). The thick- 
ness at the thinnest point shall not be less 
than 50% of the required wall thickness, 
and the average shall not be less than 
75% of the required wall thickness. When 
general corrosion is identified that exceeds 
the limits set forth in this paragraph, the 
pressure vessel shall be removed from 
service until it is repaired by a qualified 
organization or permanently removed from 
service. 



262 




Part 2, Section "7 
Inspection — NBIC Policy 
For Metrication 



2S3 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



INSPECTION 



PART 2, SECTION 7 

- NBIC POLICY FOR METRICATION 



7.1 



GENERAL 



This policy provides guidance for the use of U.S. 
customary units and metric units. Throughout 
the NBIC, metric units are identified and placed 
in parentheses after the U.S. customary units 
A08 referenced in the text and associated tables. In 
Supplement 6, Continued Service and Inspec- 
tion of DOTTransport Tanks the metric units are 
shown first with U.S. customary units shown 
in parentheses. For each repair or alteration 
performed, selection of units shall be based on 
the units used in the original code of construc- 
tion. For example, items constructed using U.S. 
customary units shall be repaired or altered 
using U.S. customary units. The same example 
applies to items constructed using metric units. 
Whichever units are selected, those units arc to 
be used consistently throughout each repair or 
alteration. Consistent use of units includes all 
aspects of work required for repairs or altera- 
tions (i.e., materials, design, procedures, test- 
ing, documentation, and stamping, etc.). 






EQUIVALENT RATIONALE 



The rationale taken to convert metric units and 
U.S. customary units involves knowing the 
difference between a soft conversion and a 
hard conversion. A soft conversion is an exact 
conversion. A hard conversion is simply per- 
forming a soft conversion and then rounding 
off within a range of intended precision. When 
values specified in the NBIC are intended to 
be approximate values, a hard conversion is 
provided. If an exact value is needed to main- 
tain safety or required based on using good 
engineering judgment, then a soft conversion 
will be used. In general, approximate accuracy 
is acceptable for most repairs or alterations 
performed using the requirements of the NBIC. 
Therefore, within the NBIC, metric equivalent 
units are primarily hard conversions. 



The following examples are provided for further 
clarification and understanding of soft conver- 
sions versus hard conversions: 

Example 1: Using 1 in. = 25.4 mm; 
12 in. = 304.8 mm (soft conversion) 

Example 2: Using the above conversion, a hard 
conversion may be 300 mm or 305 mm de- 
pending on the degree of precision needed. 



7.3 PROCEDURE FOR 

CONVERSION 

The following guidelines shall be used to con- 
vert between U.S. customary units and metric 
units within the text of the NBIC: 

a) All US customary units will be converted 
using a soft conversion. 

b) Soft conversion calculations will be re- 
viewed for accuracy. 

c) Based on specified value in the NBIC, an 
appropriate degree of precision shall be 
identified. 

d) Once the degree of precision is decided, 
rounding up or down may be applied to 
each soft conversion in order to obtain a 
hard conversion. 

e) Use of hard conversion units shall be used 
consistently throughout the NBIC wherever 
soft conversions are not required. 

Note: Care shall be taken to minimize 
percentage difference between units. 



264 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



7.4 



REFERENCING TABLES 



The following tables are provided for guidance 
and convenience when converting between US 
customary units and metric units. See Tables 
7.4-1 through 7.4-8. 

Temperature shall be converted to within 1°C 
as shown in Table 7.4-2. 



A07 



TABLE 7.4-1 

Soft Conversion Factors 

(US x Factor = Metric) 



US Customary 


Metric 


Factor 


in. 


mm 


25.4 


ft. 


m 


0.3048 


in. 2 


mm' 


645.16 


ft. 2 


m J 


0.09290304 


in. 1 


mm' 


1 6,387.064 


! ft.- 


nr 


0.02831685 


US gal. 


rri 3 


0.003785412 


US gal. 


liters 


3.785412 


psi 


MPa 


0.0068948 


psi 


kPa 


6.894757 


ft- lb 


J 


1.355818 


'"H 


°C 


5/9 x (°F-32) 


R 


K 


5/9 


Ibm 


kg 


0.4535924 


Ibf 


N 


4.448222 


in.-lb 


N-mm 


1 12.98484 


ft.-lb 


K-rn 


1.3558181 


ksiVin 


MPaVm 


1.0988434 


Bfu/hr 


W 


0.2930711 


lb/ft 3 


kg/m 1 


16.018463 


in.-vvc 


kPa 


0.249089 



Note: The actual pressure corresponding to the height 
of a vertical column of fluid depends on the local 
gravitational field and the density of the fluid, which 
in turn depends upon the temperature. This conver- 
sion factor is the conventional value adopted by ISO. 
The conversion assumes a standard gravitational field 
;g r - 9.80665 N/kgi and a density of water equal to 
1,000 kg/m', 



Fractions of an inch shall be converted accord- 
ing to Table 7.4-3. Even increments of inches 
are in even multiples of 25 mm. For example, 
40 inches is equivalent to 1000 mm. Interme- 
diate values may be interpolated rather than 
converting and rounding to the nearest mm. 

For nominal pipe sizes, the following relation- 
ships were used as shown in Table 7.4-4. 

Areas in square inches (in 2 ) were converted 
to square mm (mm 2 ) and areas in square feet 
(ft 2 ) were converted to square meters (m'). See 
examples in Tables 7.4-5a and 7.4-5b. 

Volumes in cubic inches (in.'') were converted 
to cubic mm (mm 5 ) and volumes in cubic feet 
(ft') were converted to cubic meters (nr). See 
examples in Tables 7.4-6a and 7.4-6b. 

Although the pressure should always be in MPa 
for calculations, there are cases where other 
units are used in the text. For example, kPa is 
used for small pressures. Also, rounding was to 
two significant figures. See examples in Table 
7.4-7. (Note that 1 4.7 psi converts to 1 01 kPa, 
while 15 psi converts to 100 kPa. While this 
may seem at first glance to be an anomaly, it is 
consistent with the rounding philosophy.) 

Material properties that are expressed in psi 
or ksi (e.g., allowable stress, yield and tensile 



TABLE 7.4-2 
Temperature Equivalents 


Temperature °F 


Temperature °C 


60 


16 


70 


21 


100 


38 


120 


49 


350 


177 


400 


204 


450 


232 


800 


427 


1 1 50 


621 





265 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



strength, elastic modulus) were generally con- 
verted to MPa to three significant figures. See 
example in "fable 7.4-8. 

An often seen metric pressure rating is the ex- 
pression BAR, one BAR equals 14.5 psi — to 
convert psi rating to a BAR rating, multiply by 
0.069. 



TABLE 7.4-3 

US Fractions/Metric Equivalents 




Inches 


Millimeters 




1/32 


0.8 


3/64 


1.2 


1/16 


1.5 


3/32 


2.5 


1/8 


3 


5/32 


4 


3/16 


5 


7/32 


5.5 


1/4 


6 


5/16 


8 


3/8 


10 


7/16 


11 


1/2 


13 


9/16 


14 


5/8 


16 


1 1-/1 6 


17 


3/4 


19 


7/8 


22 


1 


25 









TABLE 7.4-4 

Pipe Sizes/Equivalents 




US Customary 
Practice 


Metric Practice 




NPS 1/8 


DN 6 


NPS 1/4 


DN 8 


NPS 3/8 


DN 10 


NPS 1/2 


DN 15 


NPS 3/4 


DN 20 


NPS 1 


DN 25 


NPS 1-1/4 


DN 32 


NPS 1-1/2 


DN40 


NPS 2 


DN 50 


NPS 2-1/2 


DN 65 


NPS 3 


DN80 


NPS 3-1/2 


DN90 


NPS 4 


DN 100 


NPS 5 


DN 125 


NPS 6 


DN 1 50 


NPS 8 


DN 200 


NPS 10 


DN 250 


NPS 12 


DN 300 


NPS 14 


DN 350 


NPS 16 


DN 400 


NPS 18 


DN450 


NPS 20 


DN500 


NPS 22 


DN 550 


NPS 24 


DN 600 


NPS 26 


DN 650 


NPS 28 


DN 700 


NPS 30 


DN 750 


NPS 32 


DN 800 


NPS 34 


DN 850 


NPS 36 


DN 900 


NPS 38 


DN 950 


NPS 40 


DN 1 000 


NPS 42 


DN 1050 


NPS 44 


DN 1100 


NPS 46 


DN 1150 


NPS 48 


DN 1200 


NPS 50 


DN 1250 


NPS 52 


DN 1300 


NPS 54 


DN 1350 


NPS 56 


DN 1400 


NPS 58 


DN 1450 


NPS 60 


DN 1500 





266 




Part 2, Section 9 

Inspection — Glossary of Terms 



273 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



PART 2, SECTION 9 
JSPECTION — GLOSSARY OF TERMS 



9.1 



DEFINITIONS 



For the purpose of applying the rules of the 
NBIC, the following terms and definitions shall 
be used herein as applicable to each Part: 

Additional terms and definitions specific to 
DOT Transport Tanks are defined in Part 2, 
Supplement 6. 

A07 Accumulator — A vessel in which the test 
medium is stored or accumulated prior to its 
use for testing. 

Alteration — Any change in the item described 
on the original Manufacturer's Data Report that 
affects the pressure containing capability of the 
pressure-retaining item. Nonphysical changes 
such as an increase in the maximum allowable 
working pressure (internal or external), increase 
in design temperature, or a reduction in mini- 
mum temperature of a pressure-retaining item 
shall be considered an alteration. 

ANSI — The American National Standards 
Institute. 

ASME Code - The American Society of Me- 
chanical Engineers' Boiler and Pressure Vessel 
Code published by that Society, including 
addenda and Code Cases, approved by the 
associated ASME Board. 

Assembler — An organization who purchases 
or receives from a manufacturer the necessary 
component parts of valves and assembles, 
adjusts, tests, seals, and ships safety or safety 
relief valves at a geographical location, and 
using facilities other than those used by the 
manufacturer. 

Authorized Inspection Agency — 
New Construction: An Authorized Inspection 
Agency is one that is accredited by the National 
Board meeting the qualification and duties of 



NB-360, Criteria for Acceptance of Authorized 
inspection Agencies for New Construction. 

Inservice: An Authorized Inspection Agency 
is either: 

a) a jurisdictional authority as defined in 
the National Board Constitution; or 

b) an entity that is accredited by the Na- 
tional Board meeting NB 369, Quali- 
fications and Duties for Authorized 
Inspection Agencies Performing Inser- 
vice Inspection Activities and Quali- 
fications for Inspectors of Boilers and 
Pressure Vessels; NB-371 , Accreditation 
of Owner-User Inspection Organiza- 
tions (OUIO) or NB-390, For Federal 
Inspection Agencies (FIAs) Performing 
Inservice Inspection Activities. 

Capacity Certification — The verification by the 
National Board that a particular valve design or 
model has successfully completed all capacity 
testing as required by the ASME Code. 

Chimney or Stack — A device or means for 
providing the venting or escape of combustion 
gases from the operating unit. 

Conversion — 

Pressure Relief Devices: The change of a pres- 
sure relief valve from one capacity-certified 
configuration to another by use of manufac- 
turer's instructions. 

Units of Measure: Changing the numeric value of 
a parameter from one system of units to another. 

Demonstration — A program of making evident 
by illustration, explanation, and completion of 
tasks documenting evaluation of an applicant's 
ability to perform code activities, including the 
adequacy of the applicant's quality program, and 
by a review of the implementation of that program 
at the address of record and/or work location. 



A07 



274 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Dutchman --■■ Generally limited to tube or pipe 
cross-section replacement. The work necessary 
to remove a compromised section of material 
and replace the section with material meet- 
ing the service requirements and installation 
procedures acceptable to the Inspector. Also 
recognized as piecing. 

Examination — In process work denoting the 
act of performing or completing a task of inter- 
rogation of compliance. Visual observations, 
radiography, liquid penetrant, magnetic par- 
ticle, and ultrasonic methods are recognized 
examples of examination techniques. 

Exit — A doorway, hallway, or similar passage 
that will allow free, normally upright unencum- 
bered egress from an area. 

Field — A temporary location, under the control 
of the Certificate Holder, that is used for repairs 
and/or alterations to pressure-retaining items at 
an address different from that shown on the Cer- 
tificate Holder's Certificate of Authorization. 

Forced-Flow Steam Generator A steam gen- 
erator with no fixed steamlinc and waterline. 

Inspection — A process of review to ensure 
engineering design, materials, assembly, ex- 
amination and testing requirements have been 
met and are compliant with the Code. 

Inspector — See National Board Commis- 
sioned Inspector and National Board Owner- 
User Commissioned Inspector. 

Intervening — Coming between or inserted 
between, as between the test vessel and the 
valve being tested. 

Jurisdiction — A governmental entity with the 
power, right, or authority to interpret and enforce 
law, rules, or ordinances pertaining to boilers, 
pressure vessels, or other pressure-retaining 
items. It includes National Board member juris- 
dictions defined as "jurisdictional authorities." 

Jurisdictional Authority — A member of the 
National Board, as defined in the National 
Board Constitution. 



Lift Assist Device — A device used to apply an 
auxiliary load to a pressure relief valve stem or 
spindle, used to determine the valve set pres- 
sure as an alternative to a full pressure test. 

Manufacturer's Documentation — The docu- 
mentation that includes technical information 
and certification required by the original code 
of construction. 

Mechanical Assembly — The work necessary to A08 
establish or restore a pressure retaining bound- 
ary, under supplementary materials, whereby 
pressure-retaining capability is established 
through a mechanical, chemical, or physical 
interface, as defined under the rules of the 
NBIC. 

Mechanical Repair Method — A method of A08 
repair, which restores a pressure retaining 
boundary to a safe and satisfactory operat- 
ing condition, where the pressure retaining 
boundary is established by a method other than 
welding or blazing, as defined under the rules 
of the NBIC. 

NBIC — The National Board Inspection Code 
published by The National Board of Boiler and 
Pressure Vessel Inspectors. 

"NR" Certificate Holder — An organization in 
possession of a valid "NR" Certificate of Autho- 
rization issued by the National Board. 

National Board — The National Board of Boiler 
and Pressure Vessel Inspectors. 

National Board Commissioned Inspector — 

An individual who holds a valid and current 
National Board Commission. 

Nuclear Items — Items constructed in accor- 
dance with recognized standards to be used in 
nuclear power plants or fuel processing facilities. 

Original Code of Construction — Documents 
promulgated by recognized national standards 
writing bodies that contain technical require- 
ments for construction of pressure-retaining items 
or equivalent to which the pressure-retaining item 
was certified by the original manufacturer. 



275 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Owner or User — As referenced in lower case 
letters means any person, firm, or corporation 
legally responsible for the safe operation of any 
pressure-retaining item. 

Owner-User Inspection Organization — An 

owner or user of pressure-retaining items lhal 
maintains an established inspection program, 
whose organization and inspection procedures 
meet the requirements of the National Board 
rules and are acceptable to the jurisdiction or 
jurisdictional authority wherein the owner or 
user is located. 

Owner-User Inspector — An individual who 
holds a valid and current National Board 
Owner- User Commission. 

Piecing — A repair method used to remove 
and replace a portion of piping or tubing ma- 
terial with a suitable material and installation 
procedure. 

Pressure-Retaining Items (PRO — Any boiler, 
pressure vessel, piping, or material used for 
the containment of pressure, cither internal or 
external. The pressure may be obtained from 
an external source, or by the application of 
heat from a direct source, or any combination 
thereof. 

Pressure Test — Prior to initial operation, the 
completed boiler, including pressure piping, 
water columns, superheaters, economizers, 
stop valves, etc., shall be pressure tested in a 
test performed in accordance with the original 
code of construction prior to initial operation 
of an installed unit that is witnessed by an 
Inspector. 

Repair — The work necessary to restore pres- 
sure-retaining items to a safe and satisfactory 
operating condition. 

Re-ending — A method used to join original 
code of construction piping or tubing with 
replacement piping or tubing material for the 
purpose of restoring a required dimension, 
configuration or pressure-retaining capacity. 

Re-rating — See alteration. 



"R" Certificate Holder — An organization in 
possession of a valid "R" Certificate of Autho- 
rization issued by the National Board. 

Safety Relief Valves — A safety relief valve is 
a pressure relief valve characterized by rapid 
opening or pop action, or by opening in propor- 
tion to the increase in pressure over the opening 
pressure, depending on application. 

Settings — Those components and accessories 
required to provide support for the component 
during operation and during any related main- 
tenance activity. 

Shop — A permanent location, the address that 
is shown on the Certificate of Authorization, 
from which a Certificate Holder controls the 
repair and/or alteration of pressure-retaining 
items. 

Testing Laboratory — National Board accepted 
laboratory that performs functional and capac- 
ity tests of pressure relief devices. 

Transient — An occurrence that is maintained 
only for a short interval as opposed to a steady 
state condition. 

Velocity Distortion — The pressure decrease 
that occurs when fluid flows past the opening 
of a pressure sensing line. This is a distortion 
of the pressure that would be measured under 
the same conditions for a non or slowly mov- 
ing fluid. 

"VR" Certificate Holder — An organization in 
possession of a valid "VR" Certificate of Autho- 
rization issued by the National Board. 

Water Head — The pressure adjustment that 
must be taken into account due to the weight 
of test media (in this case, water) that is 0.433 
psi per vertical ft. (10 kPa per m.) added (sub- 
tracted) from the gage pressure for each foot A07 
the gage is below (above) the point at which 
the pressure is to be measured. 



276 




Part 2, Section 1 D 
Inspection — NBIC-Apprdved 
Interpretations 



zvv 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



PART 1, SECTION 10 

INSTALLATION — NB8C APPROVED INTERPRETATIONS 



10.1 



SCOPE 



This section provides all approved interpre- 
tations for this edition and all subsequent 
addenda associated with this edition. A 
complete listed index is provided for refer- 
ence to previously approved interpretations. 
These previously approved interpretations 
can be found on the National Board Web 
site. 



b) Each interpretation references the edition 
and addenda applicable at the time of 
committee response and approval. Use of 
interpretations for other than approved edi- 
tion and addenda may not be appropriate 
for reference. 



10.2 



INDEX OF INTERPRETATIONS 



Foreword 95-20 

Code Cases 1923 98-24 

98-56 
1945 98-24 

98-56 

2203 98-12 

Procedure for Obtaining or Renewing a National Board 

Certificate of Authorization 98-21 

07-02 
Outline of Requirements for a Quality System 

for Qualification for the National Board '"R" Symbol Stamp 98-13 

General Rules 04-02 

Condition of Use 98-02 

Nameplate Contents 98-25 

98-26 
95-26 

Use of Owner-User Personnel During Repairs 01-12 

Test Medium and Testing Equipment 98-17 

Procedure for Obtaining or Renewing a National Board 

"NR" Certificate of Authorization 98-07 

98-41 

Interface with the Owner's Repair/Replacement Program 04-16 

Prerequisites for Accreditation 98-16 

General Conditions 98-1 1 

Pressure Testing 95-38 

Inspection Interval 98-19 

Conditions that Affect Remaining Life Evaluation 01-26 

98-03 
95-57 

Operational Inspection . 95-55 

Inspection of Parts and Appurtenances 98-09 



278 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



Rcstamping or Replacement of Nameplates 98-35 

95-47 

Replacement of Stamped Data 01-13 

General Requirements 04- 1 4 

95-19 

Scope 98-22 

Construction Standard 95-36 

95-48 
04-13 

Accreditation 04-13 

Materials 01-28 

Replacement Parts 04-05 

04-06 
04-11 
04-12 
98-14 
98-27 
98-28 
98-37 
95-48 

Welding 01-27 

98-06 

95-51 

07-03 

Nondestructive Examination 04-06 

01-24 
98-10 
95-41 

Acceptance Inspection 04-21 

04-22 

Routine Repairs 04-09 

04-10 
01-19 
01-20 
01-22 
01-23 
98-01 
98-04 
98-18 
98-31 
98-42 
95-27 
95-28 
95-31 
95-33 
95-53 

Examination and Test 04-05 

04-06 
04-11 
98-27 
98-33 
98-36 
95-27 



279 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



95-32 

95-39 

95-54 
Methods 04 . 06 

04-11 

04-20 

01-15 
Documentation 01-29 

95-50 
Repair Plan 01-14 

Alterations to ASME Section VIII, Div. 2 ■' 04-14 

01-16 
Design gg.! 4 

95-22 

04-13 

Calculations 01-17 

Re-Rating " 04-03 

04-04 
01-11 
98-14 
98-15 
98-20 
98-32 
Examination and Test 98-15 

98-34 

98-38 

Methods 04-20 

Documentation 01-25 

95-50 

Repair Methods 04-01 

Scope 98_06 

Welding Method 1 04-12 

Sco P e 04-17 

04-19 

98-08 
Wasted Areas 98-42 

Re-Ending or Piecing Pipes or Tubes 98-36 

etches !.^ 04-1 5 

95-52 

Sta Y s 98-40 

Re-Rating 04 .-| 8 

Replacement Parts 04-07 

04-08 

Stamping and Nameplate Information 95-24 

Glossary of Terms 04-13 

95-21 
95-29 
95-34 
95-43 
95-45 



2BD 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 

National Board Forms 98-39 

95-25 
95-30 
95-40 
95-42 

Examples of Repairs and Alterations 01-21 

98-23 
98-29 
98-30 
95-44 
95-46 
95-48 
95-49 

Repairs 01-18 



28 1 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



10.3 SUBJECT INDEX OF INTERPRETATIONS 

Acceptance Inspection 04-13 

04-21 
04-22 

Alteration Requirements 04-14 

Alterations to ASM E Section VIII, Div. 2 01-16 

Allernalives to PWI IT 98-06 

Attachments 98-01 

Blisters, Repair of 98-09 

Calculations 01-17 

Construction Standards 04-1.3 

Deaerators, Inspection of 98-09 

Defect Repairs 04-17 

04-19 

Definition of Repair 98-23 

98-29 
98-30 
95-43 
95-45 
95-46 
95-49 

Definition of Alteration 95-21 

95-36 
95-44 
95-45 

Definition of Inspector 95-29 

Definition of Non-Load Bearing 95-33 

Demonstration Requirements 98-41 

De-Rating 98-20 

Design 04-13 

Deterioration 01-26 

Documentation 01-25 

95-50 

Examination and Test 04-05 

04-06 
04-11 
04-20 

Examples of Repairs and Alterations 01-21 

General Rules 04-02 

04-14 

Inspection Interval 98-19 

95-57 

Joint Review Demonstration Requirements 98-21 

Material Thickness 98-36 

Materials 01-28 

MTR 98-37 

Nameplates 95-24 

Non "U" Stamped Vessels 95-23 

Nondestructive Examination 04-06 

01-24 
98-10 

Nuclear Components 98-07 

Original Code of Construction 95-19 

282 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Out-ot-Servicc 98 " 03 

Owner-User Inspection 9 "~1 ' 

r 98-16 

Owner's Repair/Replacement Program 04-16 

Patches 04 " 15 

QO ) ) 

Piping rn 

Pressure Relief Valves 98 " 02 

98-13 

98-17 

98-24 

98-25 

98-26 

95-26 

95-55 

95-56 

07-01 

no i c 

Pressure Testing '"" !J 

6 98-27 

98-33 

98-34 

98-38 

95-27 

95-32 

95-39 

95-38 

Pressure Testing Repairs 01-1 j 

Qualification of WeldersAVelding Procedures 95-51 

Quality System Manual 98- 1 3 

"R" Forms JB "-™ 

95-27 

95-28 

95-30 

95-40 

95-42 

95-48 

95-50 

Repair Definition 04-13 

Repair Methods 04 -° 1 

Repairs 01 - 18 

Repair Plan 01 - 14 

r-> i r- *• 95-7? 

Reclassification VD zz 

Replacement Nameplates 98-35 

95-47 

Replacement Parts 04-05 

1 04-06 

04-08 
04-1 1 
04-12 
98-14 
98-27 
98-28 
01-29 
Replacement of Stamped Data 01-13 



283 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 

Re-Rating 04-03 

04-04 

04-18 

01-11 

98-14 

98-15 

n • n ■ 98-32 

Routine Repairs 04-09 

04-10 

01-19 

01-20 

01-22 

01-23 

98-01 

98-04 

98-18 

98-31 

98-42 

95-25 

95-27 

95-28 

95-31 

95-53 

95-54 

^ ta Y s 95-40 

Tinning of Repairs 98-05 

95-41 
Use of Editions/Addenda 95-20 

Use of Owner/User Personnel During Repairs 01-12 

Welding 01-27 

Welding Methods 04-06 

v.,- . r. ° 4 " 12 

Window Patch 95-52 



ZB4